New York Times

WASHINGTON — A decade ago, as President George W. Bush was about to appoint a Supreme Court justice, The Wall Street Journal’s editorial page pleaded with him to choose a reliable conservative. Republican presidents had made too many mistakes, it said, in appointing justices who turned out to be liberals.

“No More Souters,” the headline read, referring to Justice David H. Souter, who was appointed by the elder President George Bush in 1990 but soon started voting with the court’s liberal wing. The editorial listed other Republican appointees who had disappointed conservatives: Chief Justice Earl Warren and Justices William J. Brennan Jr., Harry A. Blackmun, John Paul Stevens and Anthony M. Kennedy.

“This is the history — which many view as political betrayal — that Mr. Bush has to confront as he makes his choice,” the editorial said.

Mr. Bush’s choice, Chief Justice John G. Roberts Jr., delighted the right. But now, 10 years later, some conservatives seem to be suffering from a belated and somewhat puzzling case of buyer’s remorse.

At the recent Republican presidential debate, candidates took turns attacking Chief Justice Roberts, calling his nomination a mistake. An advertisement that aired during the debate urged voters to “demand justices with a proven record of upholding the Constitution.”

“We can’t afford more surprises,” the ad concluded, over the images of Justices Souter and Kennedy — and Chief Justice Roberts.

In June, The Journal’s editorial page expressed worry that Chief Justice Roberts may be “moving pointedly to the left on the bench, like former Justices David Souter or Harry Blackmun.”

This barrage of criticism is hard to reconcile with Chief Justice Roberts’s overall record, which is quite conservative.

He was in the majority in 5-to-4 decisions like Citizens United v. Federal Election Commission, which amplified the role of money in politics; Shelby County v. Holder, which destroyed the heart of the Voting Rights Act; and District of Columbia v. Heller, which identified an individual right to bear arms.

When the court ruled in favor of same-sex marriage in June, again by a 5-to-4 vote, Chief Justice Roberts dissented. He summarized his dissent from the bench, a first for him and a move signaling profound disagreement.

And so the right’s case against the chief justice is thin, said Steven R. Shapiro, the legal director of the American Civil Liberties Union. “The reaction is almost entirely due to the two health care decisions,” he said, “and there is nothing else in his record that should be disappointing.”

In 2012, Chief Justice Roberts wrote the majority opinion rejecting a constitutional challenge to a central feature of President Obama’s health care law, the Affordable Care Act. In June, he wrote the majority opinionallowing nationwide tax subsidies under the law.

Those rulings were unpopular with the right, but they do not provide much evidence that Chief Justice Roberts has turned into a liberal, said Brianne Gorod, a lawyer with the Constitutional Accountability Center, a liberal group that has issued a series of reportsassessing the chief justice’s decade on the court.

“It’s just a ridiculous claim,” Ms. Gorod said. “He has been exceptionally conservative throughout his entire 10 years. They just really dislike the way he voted in the A.C.A. cases.”

In the last week of the term that ended in June, she said, the court issued six major decisions — on health care, marriage, housing discrimination,redistricting, the death penalty and the environment. Except in the health care case, Chief Justice Roberts voted with the court’s conservative wing every time.

But Carrie Severino, the chief counsel for the Judicial Crisis Network, the conservative legal group that produced the recent ad, said there was good reason to be wary of Chief Justice Roberts’s approach to his job. His health care opinions betrayed a “profoundly political” view of the law, she said. She added that he sometimes moved too slowly even when he was heading in the correct direction, pointing to a 2009 decision that put off deciding the fate of the Voting Rights Act.

“Everyone can agree that John Roberts is a significantly better justice than either Souter or Kennedy,” Ms. Severino said. “Roberts wasn’t a complete blank slate candidate like a Souter. But he was a blank slate in that we didn’t know how he would perform when he was required to stand up for his principles with courage.”

Political scientists say the conservative critique has a little merit, but not much. An analysis of voting patterns over the last decade shows Chief Justice Roberts to be well to the right of Justices Kennedy and Souter.

But a comparison of his votes with those of Justice Samuel A. Alito Jr., who was appointed by Mr. Bush in 2006, tells a slightly different story. The two started out ideologically indistinguishable. But Justice Alito has trended right, and Chief Justice Roberts left.

A recent study in The Journal of Legal Studies and related data presented an even more nuanced picture. It ranked the justices in ideological order and was prepared by Lee Epstein, a law professor and political scientist at Washington University in St. Louis; William M. Landes, a law professor and economist at the University of Chicago; and Judge Richard A. Posner of the United States Court of Appeals for the Seventh Circuit in Chicago.

They found that Chief Justice Roberts voted in a conservative direction 58 percent of the time over the last decade, while Justices Alito, Antonin Scalia and Clarence Thomas ranged from 61 to 65 percent.

But the chief justice leaned right when it mattered most. “He is a reliable conservative in the most closely contested cases but moderate when his vote cannot change the outcome,” the study said.

In 5-to-4 cases, the study found, Chief Justice Roberts voted in a conservative direction 85 percent of the time, a higher rate than that of any other member of the court.