Iowa caucuses 2020: Democrats hit the campaign trail on last day before caucuses

Warren stopped by a Super Bowl party in Des Moines hosted by some Iowa progressive groups.  She spoke only for a few minutes, saying how thankful she is for everyone who came to see her and gave her ideas.

Before departing for Washington D.C., she said she feels "good." — Zak Hudak 

Klobuchar said being in D.C. these past two weeks has been "soul-crunching."

"So I am asking you tonight to be there for me tomorrow," Klobuchar said. "I literally never imagined that I would be flying out of here tonight. And then I would be there just barely at the last minute but I have a constitutional duty. I can't turn the channel and watch something else."  — Musadiq Bidar

Sanders made it to three field office meetings on Sunday. At the first one, a Cedar Rapids field office opening, the event was moved outside because there so many people.

In addition to his stump speech, Sanders told the Cedars Rapids' crowd "tomorrow night is about understanding that we need a government that stands for justice not greed. — Cara Korte

At Biden's second-to-last campaign event in Iowa, the former vice president fired back at Senator Joni Ernst, who defended President Trump on CNN's "State of the Union." Earlier in the week, Ernst had suggested the impeachment trial will be worse for Biden than Mr. Trump.

"Let Joni Ernst know how smart you are and caucus for me!" Biden shouted to the crowd in Dubuque. The crowd responded with a standing ovation.

Shortly after, Biden declared the "words Trump fear most" are "we are gonna caucus for Joe Biden."

Biden also introduced his granddaughter, Finnegan. He said the difference between daughters and granddaughters is that with daughters you put them to bed one night at age 11 or 12 and you wake up with a "snake" in the bed the next day. With granddaughters, Biden said, they always love you — and expect you to embarrass them, as he does in these familial shout outs. — Bo Erickson

At a speech in Cedar Rapids, Klobuchar said no one thought her campaign would still be here. She said a year after starting her campaign, he is one of the top five candidates and she's been able to do it by budgeting frugally.

"I have been doing this the hard way and I have been punching way above my weight," Klobuchar said.

Her campaign said about 400 people were in attendance.  — Musadiq Bidar

The mayor of Iowa City, Iowa, endorsed Buttigieg on Sunday at Buttigieg's "Get Out the Caucus" rally in Coralville. Mayor Bruce Teague had once been surrogate for Cory Booker, who dropped out in January. — Jack Turman

The final verdict vote on impeachment is scheduled for Wednesday, with closing arguments scheduled to begin Monday at 11 a.m. The schedule will give the four senators still in the race — Sanders, Warren, Klobuchar and Bennet — a busy 24 hours.

The campaigns for Sanders, Warren and Klobuchar confirmed Sunday those three candidates will go to Washington on Sunday night and return to Iowa on Monday for the caucuses. — Cara Korte, Zak Hudak and Musadiq Bidar

President Trump took aim at former New York City Mayor Michael Bloomberg on Sunday morning, writing on Twitter "Mini Mike is now negotiating both to get on the Democrat Primary debate stage, and to have the right to stand on boxes, or a lift, during the debates. This is sometimes done, but really not fair!"

Bloomberg, who is not competing in Iowa or any of the early states, was campaigning in California on Sunday. He hit back at Mr. Trump, saying he "lies about everything so it shouldn't be a surprise."

"I stand twice as tall on the stage the stage that matters," Bloomberg said. "This is what happens when somebody like me rises in the polls all of a sudden the other candidates get scared and I think Donald Trump knows I can beat him and that's why he comes back with those kind of comments ." — Tim Perry

Buttigieg says it's "very important" for him to do well in Monday's Iowa caucuses but he'll leave it to others to define what success means.

"I'll leave that to the pundits," Buttigieg said on "Face the Nation" when asked if he must finish in the top two in the Hawkeye State. "It is, of course, very important for us to do well in Iowa."

Buttigieg's advisers have told reporters it isn't necessary for him to win in Iowa to prove he can be viable on Super Tuesday. Asked if his strategy is to skip ahead to Super Tuesday in a month, Buttigieg demurred, saying advisers and pundits will have their opinions while he's focused on campaigning and on improving the lives of everyday Americans.

• Transcript: Pete Buttigieg on "Face the Nation"

"That's great. Campaign strategists will focus on that. I'm focused on Iowans' lives and a message about making sure that we not only replace this president but replace this president with somebody who is ready to deal with the issues from climate to gun violence to the changes in our economy that are deciding whether our lives are going to go well," he said Sunday. "We're counting on a good finish here in Iowa, going straight to New Hampshire and on to Nevada, South Carolina and the other states."

Read more here.

The final CBS News Iowa Battleground Tracker offers a statistical simulation of the caucuses and some scenarios that might unfold on Monday. It looks like a close contest heading in, and the top candidates are all poised to win national delegates. 

To show what could happen — and more importantly, why — we continued interviewing likely caucus-goers this week for their first- and second-choice preferences in our polling, then combined it with data on Iowa voters generally, and how the caucus system works across the state's counties and districts.

As of Sunday, Bernie Sanders and Joe Biden even in first-choice support at 25% each in our baseline model, Pete Buttigieg very close behind at 21%, and Elizabeth Warren at 16%, also in position to accrue some national delegates. Amy Klobuchar is at 5% in our baseline estimate, and all other candidates are under 5%.

Read full results here.

A crucial Iowa poll, long considered the most credible in the state and closely watched by political campaigns and observers, will not be released Saturday night as planned, said The Des Moines Register, CNN and Selzer & Co. It's one of the final Iowa polls ahead of the state's caucus on Monday.  

"Today, a respondent raised an issue with the way the survey was administered, which could have compromised the results of the poll. It appears a candidate's name was omitted in at least one interview in which the respondent was asked to name their preferred candidate," Des Moines Register executive editor Carol Hunter said in a statement.

Hunter said the incident appears to be isolated to just one surveyor but could not confirm with certainty and "therefore the partners made the difficult decision to not to move forward with releasing the Iowa poll." — Musadiq Bidar and Adam Brewster