(CBS News) Chief Justice John Roberts surprised many conservative watchers of the Supreme Court when he wrote the majority opinion backing the Patient Protection and Affordable Care Act, which critics of President Obama had claimed was unconstitutional.
In fact, said Harvard law professor Laurence Tribe, Roberts' decision backing the health care law, including the individual mandate, was an expression of conservatism.
A professor of constitutional law at Harvard Law School, Tribe has counted both Roberts and Mr. Obama among his students.
"It seemed to me that, as a modest guy and someone who did not want the court to shatter an historic piece of legislation even though he didn't like it, John Roberts was bound to take a step that would ultimately be modest," Tribe explained on "CBS This Morning," "that would not expand government power - despite- but that would use private industry and that ultimately - as the Chief Justice made clear he understood in the very first day of the oral argument - didn't literally make anyone do anything.
"It simply said that if you do not cover yourself and your family with insurance, then you have to pay a higher tax bill than otherwise so that you don't take a free ride on other people and raise other people's premiums," Tribe said. "It was a conservative idea that a conservative Chief Justice could find acceptable as long as there was a basis for it in the Constitution.
"And that's where he differed from the four conservatives with whom he often sides - that is, he looked carefully, not just at what this law was called, but at what it did.
"And it quacked like a duck, it looked like a duck, it operated only to increase people's taxes a little bit if they go into the stream of commerce uncovered, as it were. And so it was a conservative idea."
Tribe, who argued part of Bush v. Gore before the Rehnquist Court, also said that Roberts had a responsibility to prevent the court "from falling into increasing disrepute."
A recent CBS News poll shows that. "Does this ruling change that perception?" asked Erica Hill.
"Well, we'll have to see," Tribe said. "I don't have an instant polling device in my pocket. [But] I do think this ruling helps. I think it could. I think that it's very important even though there are certainly counter-examples when the court seems to be politically driven, like Bush v. Gore, that on a case that the entire world was watching as closely as this one, that the court showed that it can transcend political preferences. ...
"After Bush v. Gore, after Citizens United, [a] deeply-divided country needs a more united, rather than deeply-divided and partisan, Supreme Court," Tribe said.
Until Thursday's opinion was announced, Chief Justice Roberts was a reliable conservative vote, especially on social issues that split the Court 5-4. 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 spending by corporations in political campaigns.
Jeff Glor asked Tribe if Roberts might replace Justice Arthur Kennedy - who is often the deciding vote in cases won by with the Court's conservative or liberal wings - as the new swing vote on the bench.
"Well, I think the whole idea of 'swingers' on the court has always been sort of more fun than real," Tribe replied. "This is the Roberts Court. It's come into its own finally, with Chief Justice Roberts in the most important case in decades playing the pivotal role. But that's all appropriate. He is, after all, the Chief Justice, not just of the court but of the United States of America."
To watch the interview with Laurence Tribe click on the video player above.