Republicans are worried about the Supreme Court, with good reason. Three conservative justices are in their 70s. With a large Democratic Senate majority, any vacancy likely won’t be filled until at least 2029, and later if Republicans hold the White House. There has been chatter about pushing the oldest justices to retire so that the lame-duck Senate can confirm successors.

“Justice Samuel Alito will be under pressure to resign, perhaps as soon as this week,” Journal reporter Damian Paletta wrote on Wednesday. Legal scholar Dale Carpenter blogged on Monday that he had heard “increasing speculation and support” from conservatives and “corresponding worry among progressives” about the possibility that Justices Alito, 76, and Clarence Thomas, 78, will retire imminently. (Curiously, no one has thrown Chief Justice John Roberts, 71, into the mix.) By all accounts, Justice Thomas has no plans to retire and may serve out his life term.

In a September Bloomberg News interview, Justice Alito ruled out a lame-duck retirement. The New York Times reported Wednesday that “two people close to the justice who spoke on the condition of anonymity” said that is still his position. For the good of the court and the country, the justices are right to stick to their guns.

Confirming a successor during a lame-duck session would be far from a sure thing, as Ed Whelan of the Ethics and Public Policy Center notes. Republicans hold 53 Senate seats, dropping to 52 on Dec. 15, when Ohio Sen. Jon Husted’s appointment expires. That means as few as three GOP defections would sink a confirmation. Mr. Whelan speculates that six Republicans might vote “no” for reasons of procedure, ideology or bad blood with President Trump.

To avoid creating a vacancy after a failed confirmation, a justice could make retirement conditional on the appointment of a successor, as Justices Sandra Day O’Connor and Stephen Breyer did. He could either specify that his retirement is effective only if the successor is confirmed before Jan. 3 or rescind his retirement if its condition is unmet when the Senate changes hands.

At least two lower-court judges have taken such an approach. Rudolph Randa, chief judge of a Wisconsin district court, said in 2007 that he would take senior status if and only if a successor was appointed before George W. Bush left office. Randa served until 2016. James Wynn of the Fourth Circuit withdrew his plan to assume senior status after Donald Trump was elected in 2024, offering no explanation. He is still active.

When a judge behaves in a political fashion, it is unseemly. If a Supreme Court justice did so, it would be inflammatory. Justices’ retirements often seem timed to ensure a congenial successor, but a retirement announcement now would be nakedly political. It would amount to an acknowledgment from the bench that the left is correct to think the court is merely another political body.

That would undercut any effort to resist court-packing legislation the next time the Democrats control both the White House and Congress. Such legislation may be enacted anyway. But inviting it would be a shameful legacy for a justice, particularly an originalist justice.

When I interviewed Justice Alito in July, I asked if he thought strategic retirements undermine the court by creating the impression that judges are political.

“I actually hadn’t thought about—I’m pausing because I hadn’t really thought about this before,” he said. “I would answer that in the same way as I would answer those who claim that voting is based on party affiliation. . . . It’s correlation, not causation. The cause is not affiliation with the Republican Party or the Democratic Party. The cause is a view of the law and the court that correlates with the party of the president who appointed the justice.”He didn’t directly answer the question about retirement, but this week has given him occasion to think about it. Mr. Taranto is the Journal’s editorial features editor.