Under that second possibility, it may not be inevitable that the filibuster rule falls. Red-state Democrats would be less likely to break ranks, and institutionalist or moderate Republican senators, like Susan Collins of Maine and Lisa Murkowski of Alaska, might be more reluctant to vote to change the chamber’s longstanding rules.

Indeed, it would be politically riskier for Mr. Trump at that point to nominate an outspoken conservative. And it might motivate him to select a more moderate nominee than if the filibuster had already been abolished, just as 2016’s political reality led Mr. Obama to pick a nominee who was older and more moderate than liberal activists preferred.

That possibility has prompted Ed Whelan, a prominent conservative legal commentator and the president of the Ethics and Public Policy Center, to argue that it is in the long-term interests of conservatives if Republicans can abolish the filibuster as part of confirming Judge Gorsuch.

“Filibuster of Gorsuch would be best possible set-up for abolition of #SCOTUS filibuster. Need strong nominees for next vacancies,” Mr. Whelan wrote on Twitter. He added: “Not saying filibuster abolition will be easy. But it will be much harder with next vacancy. Best to have fight now. Pave way to transform” the Supreme Court.

A few other voices publicly agree. Richard L. Hasen, a liberal law professor at the University of California, Irvine, has argued that Democrats should hold their fire for the next vacancy, when they will have more leverage.

And John O. McGinnis, a conservative legal scholar at Northwestern University has argued that the Democrats’ threatened filibuster this week “seems irrational” if its purpose is “to help create a Supreme Court more friendly to Democratic commitments.” Eliminating the filibuster rule, he said, would leave them “in a worse position for the rest of President Trump’s term.”