ANALYSIS/OPINION:

Great expectations is a game that everybody in Washington is eager to play. The players are particularly passionate when the prize is the U.S. Supreme Court.

Many conservatives, having watched the Supreme Court, and not Congress, become the source of much of the nation’s law over the decades of liberal dominance, lived for the day when the court would be made up of lawyers with a principled respect for the Constitution, men and women who would interpret the law as written and adopted by the various legislatures of the land.

Some of these conservatives no doubt imagined that come the revolution of the federal judiciary every Supreme Court decision would be to their liking and approval, worthy of applause and gratitude. No more law by liberal whim. But for these conservatives Donald Trump might still be a television star, grabbing Hollywood starlets by their golden locks, and the Supreme Court would be moving sharply into left field, led by Hillary Clinton’s judges.

Whatever they expected, they didn’t get a court of rubber-stamps. Chief Justice John G. Roberts Jr. has demonstrated an independence from public expectations and he has shown a willingness to vote with the court’s liberal justices on frequent occasion. He may be demonstrating the principled respect for the Constitution and the law that conservatives expected. But it’s too soon to say he has pulled a David Souter and gone over to the dark side.

He joined the liberals on the court, casting the deciding vote, ordering a closer look at the mental competence of a death-row inmate who says he can’t remember the crimes he committed. Maybe he can, and this is a ruse, but that is something the lower court must determine. Capital-punishment fans are not usually fans of going the extra mile just to make sure a murderer gets a square deal.

They often prefer the determination of Bill Clinton, who as governor of Arkansas, got on with the execution of one Ricky Rector in the midst of his first campaign for president, though the prisoner was clearly retarded. When the warden called for him to proceed to the death chamber, Rector carefully put aside a piece of pecan pie from his last meal to eat on his return from the execution. We’re paying a little more reverence for life now, whether for a guilty felon or an innocent child who survives an abortion.

Mr. Roberts further angered some conservatives when he joined a 5-4 decision to block President Trump’s attempt to curb asylum requests at the Mexican border, and in an unrelated case to prevent Louisiana from enforcing new restrictions on abortion.

The chief justice’s votes reflect a change, Josh Blackman, a professor at South Texas College of Law in Houston, tells Bloomberg News. But the professor thinks it’s too early to say this reflects a shift in his legal thinking, or whether he’s just doing the right thing by the law and the Constitution. We know, from his record as a lawyer and a judge, that he prefers incremental change, not revolutionary change, which is how conservatism, a thoughtful regard for order, differs from liberalism, which prefers to stomp through the kitchen and break dishes to accomplish its aims.

Mr. Roberts’ votes in the Mexican border case and the Louisiana abortion ruling, which sent the cases back to lower courts for reconsideration, do not necessarily indicate how he would vote on their merits at the Supreme Court.

“This may be Chief Justice Roberts taking very seriously his role as the median justice and perhaps the beginning of his being the swing justice,” says Erwin Chemerinsky, dean of the University of California Law School at Berkeley. “But I would not come to that conclusion too quickly.”

In fact, the Roberts record on the High Court shows him to be a generally reliable conservative judge, far more conservative than most of his predecessors. He invites suspicion of conservatives because he sometimes seems to be most protective of the court’s reputation, badly battered over the past few decades by the manufacture of loopy legal opinions. Partisan battles over judicial confirmations have added to the problem, as Mr. Roberts sees it.

“People need to know that we’re not doing politics,” he said in a speech last month in Nashville. “They need to know that we’re doing something different, that we’re applying the law.”

That’s as may be, but the layman isn’t interested in cute distinctions, and he understands that everything that happens in Washington is about politics, writ large. Mr. Roberts was stung by President Trump’s description of a judge appointed by Barack Obama as “an Obama judge.” He said “we do not have Obama judges and Trump judges, Bush judges or Clinton judges.”

Well, good luck with that. Washington knows better.

• Wesley Pruden is editor in chief emeritus of The Times.