For years Democrats have argued that the president should work around Congress due to the legislative branch’s supposedly deep-rooted obstinacy. As if there was an asterisk somewhere in the Constitution that says “…unless Republicans are being jerks about it.” The president has made this extraconstitutional case the centerpiece of campaigns, and his admirers have heartily cheered the idea. Not only has he changed the conversation, which might be expected, but Democratic Party leaders in the legislative branch have implored him to take power from them, undermining a vital tenet of governance for partisanship. This is the time for Republicans to reinstate some checks and balances, however fleeting it might be.

As Charles Cooke points out at National Review, stopping the nomination will require some heavy lifting. It may not even matter after next election. Not if Trump continues to do what he’s doing—win or lose. But Republicans will have to make the case that a nominee should not only be qualified, but ideologically qualified. They will have to argue that a lame duck president should not be empowered to change the composition of the Supreme Court.

Voters seem less inclined to be moved by idealistic arguments these days, so Republicans may suffer the short-term consequences. But if conservatives truly believe their rhetoric on constitutional values—all that stuff about the First and Second Amendments, about religious freedom and checks and balances—this might be the most worthwhile battle they’ve faced. Without some kind of curb on this accelerating dynamic, there’s little doubt we’re headed for post-constitutional governance.