John Roberts quips taking overseas trip after upholding Obama health care law "good idea"

Updated at 1:03 p.m. ET

(CBS/AP) FARMINGTON, Pa. - U.S. Supreme Court Chief Justice John Roberts joked that he'll be spending some time in "an impregnable fortress" now that the Supreme Court has ended a session that featured him casting the decisive vote to uphold President Barack Obama's health care law.

Responding to a question about his summer break, Roberts said he planned to teach a class for two weeks in Malta, the Mediterranean island nation.

"Malta, as you know, is an impregnable island fortress. It seemed like a good idea," Roberts said, drawing laughter from about 300 judges, attorneys and others attending a four-day conference Friday at a posh southwestern Pennsylvania resort.

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Roberts appeared Friday at a conference hosted by the Judicial Conference of the District of Columbia Circuit, one day after the Supreme Court said the federal government can require citizens to buy health insurance. The impromptu 35-minute session featured Roberts answering alternating questions from Chief Judge David B. Sentelle, of the D.C. Circuit Court, and Chief Judge Royce C. Lamberth, who heads the U.S. District Court for the District of Columbia.

Neither judge asked Roberts directly about the health care decision.

Rather, Roberts responded with the Malta quip after Sentelle asked him whether he was "going to Disneyworld" now that the court has adjourned for the summer.

The only direct question Roberts got about the landmark opinion upholding most key provisions of President Barack Obama's health care package came when those at the conference were invited to ask questions.

That's when Roberts was asked what he thought his court's legacy would be in 50 years and "how one recent opinion might fit into that" — an obvious reference to the health care decision.

"Well, I won't answer anything that has to do with the second part of that," Roberts said. But he said he hopes that the court under him is remembered as one that "did our job according to the Constitution, of protecting equal justice under the law."

Lamberth hinted at the controversial decision when he asked Roberts if it bothered him that he can't respond to his critics.

"No," Roberts said, his brief answer hanging in the air to more laughter.

The conference at Nemacolin Woodlands Resort and Spa, about 50 miles southeast of Pittsburgh, was entitled "Science and the Law." It focused on how social sciences and psychology affect the way the courts are perceived by the public, as well as how judges go about making decisions when such sciences come into play.

Roberts wasn't asked about those subjects. Instead, he answered more than a dozen questions ranging from how he decides to assign cases to his colleagues to whether social media activity is a problem among Supreme Court law clerks.

"The flat rule is 'don't do it,' but we haven't had any situations come up," Roberts said.

(Watch at left)

Roberts wrote the 5-4 opinion to end school integration based solely on race. He was part of the 5-4 majority that upheld the ban on late-term abortions and the 5-4 majority allowing unlimited corporate spending in campaigns.

Almost every conservative scholar in the country is now asking: What happened to the chief justice?

"Oh, I think everybody's surprised," said Georgetown Law professor Randy Barnett, who was among the first to argue the insurance mandate was unconstitutional.

Barnett said he's surprised because the chief justice struck down every administration argument defending the Affordable Care Act but went out of his way to approve the law under Congress' power to tax.

"As to why he decided to uphold the act under the tax power, to rewrite the law as a tax, that's something that only he really knows," Barnett said.

So what happened? Tom Goldstein, founder of SCOTUSblog -- a respected website on the high court -- said Roberts followed the law but knew he was making history.

"This is item No. 1 (of Roberts' legacy.) This is his signature statement that 'I'm not a partisan, I'm here to provide a limited backstop against excesses by the Congress, and I don't see it here,'" Goldstein said.

To conservatives, this was a signature statement, just not the right one.

"If it turns out that Chief Justice Roberts did buckle under the intense political pressure, that will not be good for his legacy as a justice," Barnett said.

There's already no question this changes the chief justice's legacy. On Wednesday, he was widely seen as partisan. In the most dramatic case of his career, he broke the mold.

In his opinion, the chief justice made a point of not endorsing the wisdom of the health care law. He said the decision was based on a general reticence to invalidate the acts of the nation's elected leaders.

In his opinion, Roberts wrote, "It is not our job to protect the people from the consequences of their political choices."