But Trump probably just threw away his only remaining chance to win in November with Wednesday’s Jeb Bush impersonation. He won the primaries with immigration control as his marquee issue; had he stuck to his guns, and still lost, the GOP Brain Trust, not to mention the Democrats, would more plausibly have been able to argue that opposition to their agenda was the reason. It still would have been a silly claim, since had he not grabbed hold of the immigration issue, the very idea of President Trump would have remained a Simpsons joke – if he’d remained consistent and still lost, it would have been despite his immigration position, not because of it. But now that he’s channeling Little Marco and Low-Energy Jeb on immigration, that story line has evaporated. Many of the voters who stuck with him through his various antics will start drifting away, so that in any state where the results are close in November could plausibly have been won if Trump hadn’t pulled a Schumer. It’s liberating, in a sense. ... His defeat will be on his head alone.