The president of the United States had a busy weekend. When he wasn’t golfing at Mar-a-Lago, excommunicating Marjorie Taylor Greene from the MAGA movement, or executing a bizarre U-turn on the Epstein Files, Donald Trump chose to plunge into shark-infested ideological waters by defending Tucker Carlson’s right to interview any damn antisemitic white supremacist he felt like interviewing, as the New York Times reported: In late October, Mr. Carlson, a top surrogate for Mr. Trump’s re-election campaign who was given a prime-time speaking slot at the Republican National Convention last year, interviewed Mr. Fuentes on his podcast. During their discussion,...