Now we get to the main point, which is that passage of this bill marks the end of Trump’s presidency. Trump (along with his supporters) seems to feel that triumphing on taxes will give him the momentum to move onto other great things. It won’t. It will offer Republicans the chance to abandon him. More than anything, this piece of legislation is what Republicans needed from the president. Trump has been a building fire that Republicans wouldn’t put out because they needed it to light their cigars. But now the G.O.P. has got what it wanted. It can puff and move along.

Trump might think what comes next is his wall or maybe even—who knows how much he dreams?—an infrastructure bill. These won’t happen. His leverage with his party will be spent. Even minor reforms to immigration policy are unlikely to happen. Trump is reportedly set to appoint Tom Cotton, the lone immigration wonk among Republicans in the Senate, to the C.I.A., where Cotton will abandon domestic legislation in favor of foreign-threat assessments. With his reputation for hawkishness, Cotton will, as the joke goes, fill a much-needed void.