The organizing principle of the #NeverTrump movement isn’t simply that Republicans should deny Donald Trump their presidential nomination, as Marco Rubio has it, but that they should also deny him the presidency should he prevail in the primary.

Some conservatives’ implicit willingness to essentially throw the race for the White House should Trump become their party’s nominee has understandably raised questions about how thoroughgoing and enduring their opposition to him will prove to be. The other Republican candidates are still promising to support Trump in the general election, and presumably some stalwart-seeming #NeverTrumpers will fall into line as well.

Another, better reason to doubt that #NeverTrump is more than a strategic effort to defeat Trump in the primary—rather than in the general election—can be found in the Senate, where #NeverTrump sentiment is about to come into exquisite tension with the Republican Party’s determination to deny President Obama’s Supreme Court nominee a fair hearing.

The tactics #NeverTrump conservatives demand of Senate Republicans are of a piece with the reactionary maximalism that gave rise to the Trump phenomenon in the first place. The person who will determine whether this final act of resistance to Obama will hold together is Iowa’s Chuck Grassley, who chairs the Senate Judiciary Committee, and thus controls whether Obama’s nominee will receive confirmation hearings, fair or otherwise. Grassley faces reelection this year and will likely be running against a formidable Democratic opponent. Obama is reportedly vetting Jane Kelly, an appellate court judge from Iowa whom Grassley has praised effusively in the past. So there’s a great deal of countervailing pressure on Grassley to break ranks from the rest of the GOP—including Senate Majority Leader Mitch McConnell, who holds that the next president should get to fill the vacancy on the Supreme Court.

How is Grassley responding to that pressure? By arguing in essence that not confirming Obama’s nominee is a compromise between liberal forces who want the seat filled according to custom and the forces of reaction that “come to my town meetings and say, ‘Why don’t you impeach those justices?’”