Impeachment trial: First day of Q&A session concludes

There was a little levity in the proceedings when Republican Senator Roy Blunt accidentally said he had a question with Senator McCaskill, his former Democratic colleague from Missouri. McCaskill was defeated by Josh Hawley in 2018. The chamber was filled with bipartisan laughter, leading Blunt to joke that it was "a terrifying thought." Hawley laughed, too, and even looked a bit red in the face at the sudden attention. Blunt, of course, meant to say that he had a question with Arizona Senator Martha McSally. 

McCaskill, noting that she and Blunt are actually friends, told MSNBC, she didn't believe that it would be "terrifying" for him. 

"I think he'd be perfectly fine if I were still in the Senate," she said.

Towards the end of the first day of the Q&A session, Senator Collins submitted a question to House impeachment managers asking why President Trump was not charged with bribery, even though the managers continue to insist there is overwhelming proof he is guilty of the offense.

"We could have charged bribery," Schiff said in response. "In fact, we outlined the facts that constitute bribery in the article, but abuse of power is the highest crime ... The facts we allege within that do constitute bribery. But had we charged bribery within the abuse of power article, I can assure you the counsel here would be arguing, 'you have charged two offenses within the same article. That makes that invalid.' ... If we split them into two separate articles, one for abuse of power and one for bribery, they would have argued, 'you've taken one crime and made it into two.'"

The Senate impeachment trial has adjourned for the night. The Q&A session will resume Thursday at 1 p.m.

The Senate has reconvened for the final hour of the first day of the Q&A session. Senate Majority Leader Mitch McConnell told senators that the proceedings would likely wrap up by 11 p.m.

The Senate is in recess for 15 minutes. Senate Majority Leader Mitch McConnell said that the Senate would reconvene at 10 p.m., and then conclude business for the night.

Senator Mitt Romney, one of the few Republicans who has expressed openness to calling witnesses, asked the president's legal team on what date Mr. Trump ordered a hold on aid to Ukraine, and what reason for the hold was presented at that time. 

Philbin couldn't give a specific date. 

"I don't think that there is evidence in the record of a specific date, the specific date, but there is testimony in the record" that employees within the Office of Management and Budget were aware of a hold as of July 3, and that there is evidence the president offered a rationale before then, Philbin said. 

Philbin added records show there was interest in what the Ukraine money was for and what other NATO members spend to support Ukraine, noting that from at least June 24 on, Mr. Trump expressed concerns about burden sharing. 

The president's legal team was asked when they first learned of Bolton's claims that the president linked Ukraine aid to investigations of Mr. Trump's political rivals. Bolton's claims were made in a manuscript of a forthcoming book that had been submitted to the White House for review, according to a report in The New York Times.

Philbin said the president's legal team first learned of the claims Sunday afternoon when the Times contacted the White House for comment. 

Philbin added the White House counsel's office has no role in vetting Bolton's book for possible classified information. That's the NSC's job, Philbin said. 

Senator Mark Warner, the Democratic vice chair of the Senate Intelligence Committee, submitted a question asking whether additional information exists related to Russia's dissemination of conspiracy theories embraced by Mr. Trump and Giuliani — and whether the Senate should have that information before deliberating a verdict.

Schiff, who is chairman of the House Intelligence Committee, replied that senators should take the time to review supplemental testimony by an aide to Vice President Mike Pence that remains classified. But he added that the House and Senate committees have been provided a "second body of intelligence" that is "relevant to this trial that you should also read."

"We should figure out the mechanism that would permit you to do so, because it is directly relevant to the issues we are discussing and pertinent," Schiff said. 

One potential solution would involve Senate leaders asking the intelligence community to make the material available to all senators, not just committee members, an aide told CBS News. 

Schiff, however, also noted that the intelligence community has failed to produce other material he said is relevant to the case. He said the NSA "been advised not to provide" evidence it has collected, which he called part of "a deeply concerning and new phenomenon."

Democratic Senator Joe Manchin raised comments from Dershowitz in 1998 during the Clinton impeachment in a question to both House managers and Mr. Trump's legal team, regarding whether a technical crime must be committed for a government official to be impeached and convicted by the Senate.  

"The Framers took the words 'high crimes and misdemeanors' straight out of English law, where it had been applied to impeachments for 400 years before our Constitution was written. The Framers were well aware when they chose those words that Parliament had impeached officials for high crimes and misdemeanors that were not indictable as crimes," Manchin, of West Virginia, asked in his written question. "The House has repeatedly impeached and the Senate has convicted officers for high crimes and misdemeanors for things that were not indictable crimes."

Manchin added that "even Mr. Dershowitz said in 1998 that an impeachment offense 'certainly doesn't have to be a crime.'"

"What has happened in the past 22 years to change the original intent of the famers and the historic meaning of the term high crimes and misdemeanors?" Manchin asked.

Dershowitz, answering first, said that since Clinton's impeachment proceedings, he refined his views.

"What happened since 1998 is that I studied more, did more research, read more documents and like any academic, altered my views," he said. "That's what happened. That's what professors ought to do."

Dershowitz said the framers rejected "maladministration" as a criterion for impeachment and said a synonym for maladministration is abuse of power, the first article of impeachment against Mr. Trump.

"The issue is not whether a crime is required," he said. "The issue is whether abuse of power is a permissible constitutional criteria, and the answer from the history is clearly, unequivocally no."

Nadler, however, said the main meaning of "high crime and misdemeanor" was abuse of power.

"Crimes and impeachment are two different things," he said. "Impeachments are not punishments for crimes. Impeachments are protections of the republic against the president who has abused his power."

Nadler added that the limits of an impeachment underscore why a president need not commit a crime to be removed from office.

"That is why punishment upon conviction for impeachment only goes to removal from office," he said. "Can't put him in jail as you could for a crime. You can't fine him as you could for a crime. They're two different things. An impeachment offense need not be a crime. And a crime need not be an impeachment offense."

Charles Cooper, attorney for Bolton, said the NSC has not offered further guidance about Bolton's manuscript since Cooper last asked for clarity as soon as possible. 

Cooper shared an email he sent to Ellen Knight, a National Security Council senior director, on January 24, one day after Knight wrote to Cooper to inform him Bolton's book contained classified information that could not be published. 

In the email, Cooper told Knight that "we do not believe that any of the information could reasonably be considered classified," but said he and Bolton were seeking guidance as soon as possible given the prospect of Bolton being called to the Senate as a witness.

In a statement, Cooper said he has "received no response whatever to my urgent request for the NSC's immediate guidance as to concerns as to concerns it may have with respect to the chapter of the manuscript dealing with Ambassador Bolton's involvement in matters relating to Ukraine."

Schiff pushed back on the claim from Mr. Trump's defense team that they didn't know the details of Bolton's unpublished manuscript, noting the response from Philbin was a "very carefully worded one."

Schiff, who answered on behalf of the House managers, was asked by Democratic Senators Kamala Harris and Patty Murray whether new evidence would continue to come to light after the Senate renders its verdict if they did not allow for additional testimony and documents. 

The California Democrat said new information has been revealed nearly every week since the impeachment vote. Additionally, lawmakers know new details will be revealed March 17, when Bolton's book hits shelves, barring any redactions from the National Security Council, he said.

"What I thought I heard them say in the answer to that question — what did they know about the manuscript and when did they know it — their statement was very precisely worded: The NSC unit reviewing the book did not share the manuscript," Schiff said. "Well, that's a different question than whether the White House lawyers found out what's in it, because you don't have to circulate the manuscript to have someone walk over to the White House and say, 'You do not want John Bolton to testify. Let me tell you, you don't want John Bolton to testify. You don't need to read his manuscript because I can tell you what's in it.'"

In an earlier question submitted by senators, White House lawyers were asked when they learned about the unpublished manuscript submitted by Bolton to the National Security Council.

Schiff fielded a question about the whistleblower whose complaint about the president's dealings with Ukraine ultimately led to his impeachment. 

In August 2019, a staffer on Schiff's committee advised the still-anonymous intelligence community employee to report his or her concerns to the intelligence community inspector general. Republicans have accused Schiff and his staff of acting improperly and lying about it afterward.

"I don't know who the whistleblower is. I have never met them or communicated with them in any way," Schiff said. "My staff acted at all times with complete professionalism."

He said his staff had endured threats and harassment for their work, and stressed the traditional bipartisan consensus on the importance of protecting whistleblowers.

Republican Senators Susan Collins and Lisa Murkowski, two of the Republicans most likely to call for witnesses in the trial, asked the president's legal team if they could point to a time before Joe Biden entered the presidential race that President Trump raised concerns about corruption with the Bidens or Burisma. 

Philbin took the question, claiming he couldn't reference any information that didn't appear in the record the House transmitted to the Senate, although there is no specific rule saying that. Philbin said he couldn't point to anything in the record that shows the president raised concerns prior to Biden's entry into the race.

"I'm limited to what's in the record," Philbin said. "I can't point to something in the record that shows President Trump at an earlier time mentioning specifically something related to Joe or Hunter Biden."

Philbin went on to describe how the president seemed to get his information from Giuliani, who was probing matters into Ukraine well before Biden officially announced his candidacy in April 2019. 

"The president, it seems from that, gets information from Rudy Giuliani," Philbin said.

The president's legal team was asked when the White House learned about Bolton's book and the manuscript submitted to the National Security Council, but couldn't give a specific date. The president's legal team was also asked if they did anything to attempt to block Bolton's manuscript from becoming public. 

Philbin told the Senate he didn't know off the top of his head "the exact date" the manuscript was submitted to the NSC. But at some point after the manuscript was submitted to NSC, "the White House counsel's office was notified that it was there." 

Philbin went on to read a letter from the NSC to Bolton's lawyer dated three days before the first New York Times story about the manuscript.

In a conference call with reporters Tuesday afternoon, a source on the president's legal team wouldn't say whether anyone on the legal team had been briefed on Bolton's manuscript, although the source said no members had reviewed it.

"I'm not going to get into any details beyond that. You know, no one on the legal team has reviewed the manuscript, and we're not going to get into further details," this person told reporters.

A trio of GOP senators submitted a question to the president's legal team regarding reported ties between the alleged whistleblower — whose complaint to the intelligence community inspector general sparked the impeachment inquiry — and two former National Security Council officials who now work for the House Intelligence Committee.

Senators Mike Lee of Utah, Ted Cruz of Texas and Josh Hawley of Missouri asked Mr. Trump's attorneys in their question submitted to the chief justice whether they had "reason to believe" they knew each other and "coordinated to fulfill their reported commitment to 'do everything we can to take out the president.'" No major news outlet confirmed the alleged links. 

Philbin said the only knowledge they have "comes from public reports" and he did not "want to get into speculating about that."

Senator John Barrasso of Wyoming did not directly answer whether he believes Republicans have enough votes to block witnesses. But he expects the Senate will deliver "final judgment" on that matter Friday. 

"The momentum is clearly in the direction of moving to final judgment on Friday," Barrasso said. "That vote will be Friday. still have a couple members who want to say they want to listen to the answers to questions, but that's where the momentum is."

Senators will have roughly 13 hours left to question the House managers and the president's legal team. 

Democrats need four Republicans to cross over and vote for witnesses, like Bolton. 

Jay Sekulow, one of the president's lead attorneys in the impeachment trial, rejected the assertion from Democrats that the chief justice could make the determination on whether executive privilege can be invoked.

"With no disrespect to the chief justice, the idea that the presiding officer of this proceeding could determine a waiver or the applicability of executive privilege would be quite a step," Sekulow said. "There's no historical precedent that would justify it."

The argument from Sekulow came in response to a question from GOP Senator Pat Roberts of Kansas, who asked the president's legal team to address previous claims from the House managers.

Sekulow said a ruling by the chief justice on executive privilege would raise other issues, including of speech and debate clause privilege if Mr. Trump's lawyers were, for example, to call Schiff as a witness.

"If witnesses are called by House managers through that motion, well the president's counsel would have the opportunity to call witnesses as well, which we would," Sekulow said.

Roberts was forced to read a question about the role he may play as the officer presiding over the impeachment trial if additional witnesses are called.

The question was submitted by Delaware Senator Tom Carper, a Democrat, to House managers.

"Some have claimed that subpoenaing witnesses or documents would unnecessarily prolong this trial. Isn't it true that depositions of the three witnesses in the Clinton trial were completed in only one day each and isn't it true that the chief justice, as presiding officer in this trial, has the authority to resolve any claims of privilege or other witness issues without any delay?" Roberts read.

Congressman Hakeem Jeffries answered for the managers.

"Mr. Chief Justice, the answer is yes," he said.

Jeffries noted that the record compiled by the House and submitted to the Senate showed up to five depositions per week were completed during its impeachment inquiry, demonstrating any future depositions can be completed "in an expeditious fashion."

"This is a trial. A trial involves witnesses. A trial involves documents. A trial involves evidence," Jeffries said. "That is not a new phenomenon for this distinguished body."

The New York Democrat pointed to the previous 15 impeachment trials held by the Senate — only two involved presidents — and said in each of those, witnesses were called.

"Why should this president be treated differently, held to a lower standard at this moment of presidential accountability?" Jeffries asked.

Alan Dershowitz, a member of Mr. Trump's legal team, argued the president can engage in a quid pro quo to help win reelection if he believes it is in the national interest. He said the only type of quid pro quo that is impeachable is one in which the "quo" is "in some way illegal."

"Every public official that I know believes that his election is in the public interest. And mostly you're right, your election is in the public interest," Dershowitz said. "If a president does something which he believes will help him get elected in the public interest, that cannot be the kind of quid pro quo that results in impeachment."

He cited actions President Abraham Lincoln took in the Civil War to ensure Union soldiers could return home to vote for his reelection in 1864.

"How many presidents have made foreign policy decisions after checking with their political advisers and their pollsters? If you are just acting in the national interest, why do you need pollsters? Why do you need political advisers? Just do what's best for the country," he continued. "But if you want to balance what's in the public interest with what's in your party's electoral interests and your own electoral interests, it's impossible to discern how much weight is given one to the other."

Schiff soon responded to that argument from Dershowitz, insisting that cheating in order to be reelected is exactly the type of corrupt behavior the founders were attempting to prevent from happening repeatedly. 

"That is clearly not what any rational Framer would have written and indeed they didn't," Schiff said.

— Stefan Becket and Kathryn Watson

Although the proceedings started late, senators seemed far more eager to get to the business of the day than they have before, especially compared to the past few days. 

Viewed from the press gallery, there are a few formal procedures for the question period. A Senate page who collects a question card from the senator must walk down the middle aisle of the chamber, meaning it can take some time before the question actually gets to the chief justice.

The White House legal team created cards with the numbers "2," "1" and "30," meant to indicate how much time a speaker has left — 2 minutes, 1 minute, 30 seconds. The House managers have no such system, as evidenced by Roberts cutting off Schiff and other managers at times. After the first few questions, however, the White House team seemed to abandon use of their cards.

Senators are also whispering among themselves more openly than they have been. Republicans Tim Scott, Ben Sasse and Rob Portman were chatting and laughing regularly, with Richard Burr turning around once to offer a comment. Patrick Toomey and Kevin Cramer were also whispering rather loudly at one point. Joni Ernst was filing her nails for a few minutes.

Democrat Kirsten Gillibrand also had a rather animated conversation with Brian Schatz, looking very annoyed.

White House lawyers and managers are clearly debating each other by proxy. When Republican John Thune asked the White House attorneys to respond to the House managers previous answer, there was loud, performative laughter from the Republican side.

Meanwhile, Mitt Romney, Lisa Murkowski and Susan Collins, who submitted the first question, are taking regular notes. Collins is the most assiduous note-taker.

Senator Ed Markey, a Democrat, asked the House managers to clarify whether Bolton was asked to testify in the House, after the president claimed on Twitter that he wasn't.

"The Democrat controlled House never even asked John Bolton to testify. It is up to them, not up to the Senate!" the president tweeted on Monday.

Schiff delivered the response. 

"Of course we asked John Bolton to testify in the House, and he refused," Schiff said.

But the House declined to issue a formal subpoena for Bolton, who had indicated he would go to court to contest it. Schiff said House Democrats feared that process could take "years" and pointed out that Bolton's deputy, Charles Kupperman, sued House Democrats in an effort to avoid testifying.

Minority Leader Chuck Schumer was first up for Senate Democrats to submit a question for the House managers, which centered around their efforts to secure additional testimony and documents.

"John R.  Bolton's forthcoming book states that the president wanted to continue withholding $391 million in military aid to Ukraine until Ukraine announced investigations into his top political rival and the debunked conspiracy theory about the 2016 election," Schumer's question stated. "Is there any way for the Senate to render a fully informed verdict in this case without hearing the testimony of Bolton, Mulvaney and the other key eyewitnesses or without seeing the relevant documentary evidence?"

Schiff rose to respond for the impeachment managers.

"The short answer to that question is no," he said. "There's no way to have a fair trial without witness and when you have a witness who is as plainly relevant as John Bolton, who goes to the heart of the most serious and egregious of the president's misconduct, who has volunteered to come and testify, to turn him away, to look the other way I think is deeply at odds with being an impartial juror."

Senator John Thune, a Republican, then submitted a question to Mr. Trump's lawyers asking for their response to Schiff's response to Schumer's question.

The Senate trial officially resumed just after 1 p.m., with Senator Susan Collins of Maine rising to ask the first question of Mr. Trump's counsel on behalf of herself, Romney and Murkowski.

The question was submitted to Roberts, who then read it aloud.

"If President Trump had more than one motive for his alleged conduct,such as the pursuit of personal political advantage, rooting out corruption and the promotion of national interests, how should the Senate consider more than one motive in its assessment of article one?" Roberts asked on behalf of the three Republicans.

Deputy White House counsel Patrick Philbin argued Democrats failed to show there was "no possible public interest at all" in Mr. Trump pushing for investigations into the Bidens.

"Once it is established there is a legitimate public interest ... the managers' case fails, and it fails under their own terms," Philbin said. "They've totally failed to make that case."

House Foreign Affairs Committee Chairman Eliot Engel, a Democrat from New York, revealed that Bolton suggested his panel investigate the abrupt removal of U.S. Ambassador Marie Yovanovitch from her post in Kiev in 2019. Engel said Bolton raised the issue "unprompted" during a telephone conversation shortly after he left the White House in September.

Engel said his staff reached out to Bolton at his request on September 19, as he wanted to ask if the former national security adviser would speak with the Foreign Affairs Committee "to aid our general oversight efforts on U.S. foreign policy." Bolton was ousted from his post September 10. Mr. Trump says Bolton was fired, while Bolton says he resigned. 

The two spoke by phone on September 23. During the conversation, Bolton "strongly implied that something improper had occurred around her removal as our top diplomat in Kyiv," Engel said in the statement, referencing Yovanovitch, who was abruptly recalled in May.

Engel said he kept the conversation private at the time but told his colleagues investigating Mr. Trump's dealings with Ukraine "because this detail was relevant to the Foreign Affairs, Intelligence, and Oversight Committees' investigation into this matter."

"Ambassador Bolton has made clear over the last few months that he has more to say on this issue," Engel said. "And now that the president has called his credibility into question, it's important to set the record straight."

Engel added that the attacks on Bolton from Mr. Trump's supporters underscore the need for the Senate to subpoena him for testimony.

In a tweet Tuesday night, the president questioned why Bolton didn't "complain about this 'nonsense' a long time ago, when he was very publicly terminated."

Republican Senator Mitt Romney, one of the few Republicans who is expected to vote to hear from witnesses, told reporters he wasn't sure how many of his Republican colleagues will vote to allow witnesses.

"Well, I haven't got a nose count," Romney said. "I think you saw over the last couple of days that a number of people were thinking about the witness issue."

"I can only tell you where I am and I'm going to be one of those in favor of calling witnesses. I'm sure there'll be others, how many that will be on my side of the aisle, I just don't know," Romney continued.

Speaking with reporters on Capitol Hill, Parnas responded to criticisms of him from his one-time associate, Rudy Giuliani, who called Bolton a "backstabber" in an interview with "CBS This Morning."

"Giuliani has to look in the mirror," Parnas said. "He calls everybody a backstabber but he doesn't know loyalty if it hit him in the face."

Parnas arrived on Capitol Hill with his attorney, Joseph Bondy, for the Senate's impeachment trial. While he received permission from the court to travel to Washington, his request to remove his ankle monitor was denied.

Parnas told reporters he is willing to testify under oath before lawmakers and invited Giuliani, Mr. Trump, and Secretary of State Mike Pompeo to do the same.

Republican Senator Lisa Murkowski of Alaska met with McConnell for 20 to 30 minutes on Wednesday morning on Capitol Hill. She did not reveal what the two discussed.

"I'm not going to share my personal thoughts with you this morning," Murkowski told waiting reporters.
 
Murkowski is among a small group of Republican senators being closely watched by both the White House and Democrats as potential supporters of additional witnesses. — Alan He

Mr. Trump joked about the ongoing impeachment trial during the signing ceremony for the U.S.-Mexico-Canada Trade Agreement at the White House, quipping that maybe he was "being nice" to the Republican senators in attendance in order to get their vote.

"Maybe I'm being nice to them because I want their vote. Does that make sense?" Mr. Trump joked.

He praised Republican Senator Ted Cruz, saying Cruz is eager to ask questions in the trial.

"He's dying to get back there and ask those questions," Mr. Trump said. "He's got some beauties, I'll bet." 

Parnas, the indicted associate of Rudy Giuliani who has provided hundreds of records of conversations about Ukraine to House investigators, arrived on the Hill and headed for Schumer's office:

Parnas had hoped to attend the Senate trial, but won't be able to because of an ankle monitor he must wear as part of his pretrial release. His attorney said he would be in Washington "to show support for a fair trial, with witnesses and evidence."

Schumer told reporters Parnas' testimony isn't a priority, since he "wasn't in the room where it happened."

Democratic Senator Sherrod Brown said Republicans are afraid of McConnell and the president. 

The Ohio senator said his GOP colleagues are worried the president will campaign against them in their own states as they face primary opponents. Brown said Republicans who aren't committing to voting for documents and witnesses need to "grow a spine." 

Mr. Trump tweeted, inaccurately, that no Republican witnesses were allowed to testify during the House proceedings. That simply isn't true.

"Remember Republicans, the Democrats already had 17 witnesses, we were given NONE! Witnesses are up to the House, not up to the Senate. Don't let the Dems play you!" the president wrote Wednesday morning. 

But Republicans called several witnesses during the House proceedings — lawyer Jonathan Turley, former National Security Council official Tim Morrison, State Department official David Hale and former diplomat Kurt Volker were all called to testify at the request of Republicans.

Republicans did have to receive Democratic approval to call witnesses, one reason why the whistleblower and the Bidens never testified in the House.

Republican Senator Susan Collins of Maine told CBS News the White House is doing "nothing" to get her to change her mind and oppose additional testimony.

Collins, who supports hearing from more witnesses, said there have been "a lot of discussions" among Republican senators about hearing from Bolton. 

"But I have no idea how the votes are going to fall," she said on Capitol Hill. She told "CBS This Morning" she is "very likely" to vote to allow witnesses.

Collins and GOP Senator Mitt Romney have publicly said they are open to voting to call additional witnesses during the Senate trial. 

Under the rules of the proceedings, a vote on whether to consider more testimony and documents will be held once senators conclude their questioning, which begins Wednesday afternoon.

"It was important that we hear both sides present their cases, because otherwise we wouldn't know who we might need, what gaps remain," Collins said. "And it's also very important that there be fairness, that each side, being able to select a witness or two."

A top White House adviser working on impeachment told CBS News the White House is making the case to four Republicans open to more witnesses — Collins, Romney, Senator Lisa Murkowski and Senator Lamar Alexander — for why they shouldn't support Democrats' push for witnesses. — Nancy Cordes, Paula Reid and Melissa Quinn

Democratic Senator Joe Manchin believes Hunter Biden is a relevant witness in the impeachment trial, he said in an interview on MSNBC on Wednesday morning. Manchin, who represents West Virginia, is one of the few Democrats who appears open to voting to acquit Mr. Trump.

White House attorneys have accused former Vice President Joe Biden of pushing to remove a Ukrainian prosecutor general to protect a gas company that employed Hunter Biden. Some Republican senators have called for a "one-for-one" witness exchange, in which Democrats would call Bolton as a witness in return for hearing from Joe or Hunter Biden.

Manchin said he would "absolutely" vote to call Hunter Biden as a witness if it is deemed "pertinent."

"I want witnesses, I want people to tell me what you know. You're asking me to make the most important decision I've ever made in the critical arena that I'm in or as an individual and I want to hear everything I can," Manchin said. "I want to make sure that the decision I make is the right decision."

Manchin also told reporters in the Capitol Wednesday morning that he wanted Roberts to rule on the relevance of Biden's testimony.

McConnell wasn't kidding when he asked senators to be "thoughtful and brief" with their questions. Senators who wish to ask questions of the House managers or president's defense team will have a spare six lines to write questions for Roberts to read aloud during the 16-hour Q&A period. 

Following the end of arguments from Mr. Trump's legal team on Tuesday, McConnell provided senators with a roadmap for the written question round of the proceedings, which he said Schumer agreed to.

The next phase will last two days beginning Wednesday, when the Senate will reconvene at 1 p.m. Senators will have up to eight hours during that session to submit written questions to each side. Questions will alternate between the Republicans and Democrats, McConnell said.

On Thursday, the Senate will resume time for written questions, again alternating between the majority and the minority parties, with up to eight hours allotted for the queries of the president's lawyers and House managers.

Questions must be in writing and submitted to the chief justice. McConnell urged his colleagues to be "thoughtful and brief," as they were during the impeachment trial for President Bill Clinton in 1999, and encouraged the House managers and president's counsel to be "succinct" with their answers.

"I hope we can follow both of these examples during this time," McConnell said.

Roberts quoted the late Chief Justice William Rehnquist's advice to counsel on both sides when he presided over the proceedings in 1999 "that the chair will operate on a rebuttable presumption that each question can be fully and fairly answered in five minutes or less."

"The transcript indicates that the statement was met with 'laughter,'" Roberts said to laughs of his own in the Senate chamber. "Nonetheless, managers and counsel generally limited their responses accordingly. I think the late chief's time limit was a good one and would ask both sides to abide by it."

McConnell doesn't have the votes to block witness testimony yet, a GOP source tells CBS News. A handful of Republican senators are still undecided and want to see how the Q&A session goes before making their decision. 

Senators Mitt Romney and Susan Collins have both publicly expressed being open to voting to subpoena witnesses. In addition, the White House is concerned Senators Lamar and Lisa Murkowski would also vote in favor of hearing witness testimony.  

"We need to chisel four down to two," a White House official told CBS News on Tuesday. "We are comparing notes with the leader's office. I would say we are at DEFCON 2."

Should any vote end in a 50-50 tie, Roberts would be called on to cast the deciding vote. The White House is confident Roberts would not break the tie in favor of hearing witness testimony, but would prefer the vote fail outright, the official said. — Major Garrett and Nancy Cordes