WASHINGTON-In the summer of 2005, when the Senate was considering John Roberts' nomination to the Supreme Court, the Democrats were mainly the ones concerned about his lack of judicial record. Roberts had spent his career lawyering for Republican administrations and at private firms, but his judicial philosophy was a big gray blob.

"We need to know what kind of Supreme Court justice John Roberts would be," insisted Sen. Patrick Leahy, D-Vt., then the top Democrat on the Senate Judiciary Committee. Roberts, in his confirmation hearings, was vague and safe, like most Supreme Court nominees are now post-Robert Bork. He famously compared his job to an umpire calling balls and strikes.

But even then there were clues about the philosophy of the chief justice who would become the key vote upholding President Obama's healthcare law this year. People who knew Roberts throughout his life-at Harvard, in the Washington legal world-noticed his respect for "institutions," and most especially for the court as an institution. Today many of the legal minds parsing Roberts' healthcare decision think he sided with the liberal justices to bolster the court's institutional reputation as minimalist rather than activist.

"By temperament, he's not a flame-thrower, not somebody you'd expect to willingly or readily overrule a precedent," Paul Mogin, a roommate of Roberts at Harvard Law School for two years, told The New York Times in 2005. "He's somebody who has respect for institutions. I think institutions have been important to him in his life, like Harvard, the Catholic Church and the Supreme Court. He's not likely to be anybody to do anything too radical." And Bill Kayatta, who worked on the Harvard Law Review with Roberts, told the Times, "He had a sort of thoughtful respect for institutions, history, precedent, a willingness to consider change but not revolutionary."

John Yoo, a conservative lawyer at the University of California's Berkeley School of Law, was more blunt to The Washington Post at the same time: "He's the type of person that business conservatives and judicial-restraint conservatives will like but the social conservatives may not like ... he represents the Washington establishment. These Washington establishment people are not revolutionaries, and they're not out to shake up constitutional law. They might make course corrections, but they're not trying to sail the boat to a different port."

Upon his nomination to the court in 2005, Roberts noted his "profound appreciation for the role of the court in our constitutional democracy and a deep regard for the court as an institution."

Roberts is the product of what some deem elite institutions. He grew up in Indiana along Lake Michigan, the son of a Bethlehem Steel executive. He attended private Catholic schools, excelled at Latin, and captained his football team in high school. At his all-boy boarding school, he played Peppermint Patty in a production of You're a Good Man, Charlie Brown. He attended Harvard, graduated summa cum laude, and went on to Harvard Law where he helmed the Harvard Law Review.

Out of law school, Roberts quickly leapt to legal prominence, clerking for a circuit court judge and then for Chief Justice William Rehnquist. He was counsel in the upper echelons of the Reagan administration, then left for a private firm, then returned to work in the senior Bush's administration. After President George H.W. Bush lost reelection, Roberts returned to a lucrative practice in a D.C. law firm, where he argued dozens of cases before the Supreme Court. In 2003 President George W. Bush nominated him to the D.C. Circuit Court of Appeals, where he served for two years before Bush nominated him to fill Justice Sandra Day O'Connor's seat on the Supreme Court.

A couple months after Bush nominated Roberts, in the midst of Hurricane Katrina, Rehnquist died. He was 80 years old. Bush elevated Roberts, one of Rehnquist's pallbearers, to the nomination of chief justice. An overwhelming majority of the Senate, including about half the Democrats, confirmed Roberts-though then-Sen. Barack Obama voted against his confirmation. At age 50 Roberts was the youngest chief justice in a century, and he arrived with just two years of experience as a judge, providing very little record of what kind of chief justice he would be.

A prominent figure in the Bush world before he became chief justice, Roberts came under criticism from senior Bush advisers after the healthcare decision. Michael Gerson, an advisor to President George W. Bush, blasted Roberts in a column. Dana Perino, Bush's press secretary, said on Fox News that she talked to President Bush about the healthcare decision but she declined to share the details of their conversation. "Almost across the board, every conservative said he's a solid guy, he's the one we want," she said about the nomination process. "And now the level of disappointment amongst a lot of people, including myself, is really high."

Of the 12 justices Republican presidents have nominated since President Richard Nixon, at least seven have "drifted left," or denied conservatives a majority on significant cases. Chief Justice Warren Burger voted with the majority in Roe v. Wade. Justice John Paul Stevens became the court's "liberal lion." Justice Anthony Kennedy voted to uphold Roe, Justice David Souter became reliably liberal, and O'Connor became a swing vote. Since Nixon's administration, Democratic presidents have appointed four justices, all of whom have remained reliably liberal.

"In the way that I know John Roberts, nothing that's happened has changed my opinion of his character," said Rob Schenck, who has a pastoral relationship with the Catholic chief justice. "I know some are worried that he's 'growing in office.' I've not seen anything like that." Schenck, an ordained minister of the Evangelical Church Alliance who heads the D.C.-based outreach to Washington leaders called Faith and Action, quickly asserts that he is not a lawyer, so he is simply defending Roberts' integrity.

Everyone in Washington is parsing Roberts' motives for voting with the liberal justices on such a major case. Jan Crawford of CBS News reported that at a meeting where only the justices were present, Roberts initially voted with the conservative justices that the individual mandate was unconstitutional. But as the term neared its conclusion, he switched his position. Some think he caved to political pressure from Democrats. Others think Roberts really does have a minimalist view of the court, and he decided to rein in the court's influence over American life and let Congress do its job. (But Roberts has overturned federal statutes in the past, most famously in the Citizens United case that threw out certain campaign finance laws and changed campaigns completely.)

"If Roberts' supporters are right"-that Roberts ruled the way he did to preserve the court's reputation-"this decision was made politically. It was not a legal decision," said Randy Barnett, a conservative constitutional expert at Georgetown Law School. "He is the only jurist with any connection to this case who held this position," Barnett continued, referring to Roberts upholding the individual mandate based on Congress' taxing power. "How compelling is that? Everyone's been looking at this case for two years."

Still others think Roberts pulled off a triple Lutz jump, solidifying the conservative court's reputation as moderate and minimalist while gutting the legal framework behind the healthcare law. Former circuit court judge Michael McConnell, who was along with Roberts on Bush's short list for Supreme Court nominees, told me Roberts' opinion was "quite deft" even though he thinks the healthcare law is a "disaster."

"I think he has a genuine commitment to judicial restraint, and we saw that," McConnell said. "I think he also has a long-term desire to make the Supreme Court less of a controversial and politically charged institution." In pursuing that goal in this case, McConnell said, Roberts established tight limits on federal power: "If you think about the case raising long-term constitutional questions, the challengers [of the healthcare law] prevailed on all the important points."

Those in McConnell's camp point primarily to the part of Roberts' opinion that declares the mandate unconstitutional under the Commerce Clause, or the federal government's power to regulate-which would amount to a significant curb on a federal power that has swelled over the last century.

But some legal experts wonder whether that part of the decision will last. "Although a majority of the court agreed on a limitation of the Commerce Clause, there's at least disagreement about whether a future court would view this as binding precedent," said Jordan Lorence, a constitutional lawyer with the Alliance Defense Fund. The four liberal justices dissented from that part of the opinion. The four conservative justices agreed in substance with Roberts on that part of the opinion, but they noticeably did not join his opinion.

Usually when dissenting justices agree with the majority on a part of the opinion, their dissent will say they concur with the majority on that portion. But the four conservative justices refused to concur, which is so unusual that court observers thought the dissent was an expression of the conservative justices' deep anger with Roberts. Usually a dissent argues with the majority opinion point by point, but in the healthcare dissent the four justices barely acknowledge that Roberts' majority opinion exists.

"The court regards its strained statutory interpretation as judicial modesty. It is not. It amounts instead to a vast judicial overreaching," read Kennedy wearily on June 28 from the dissent's blistering conclusion, one of the only parts that acknowledges the majority opinion. CBS News reported that Kennedy intensely lobbied Roberts to come back to the fold after he switched his vote, to no avail. In the past, Kennedy, a Republican appointee, has received the label of "traitor" himself. He and O'Connor voted with the liberal justices in 1992 in Planned Parenthood v. Casey, a case that reaffirmed Roe v. Wade. But his alignment in that case jibes with what he sees as protecting individuals from government. That "betrayal" perhaps made more sense than Roberts' decision to uphold a mandate he thought was unconstitutional on its face.