They also have to believe that supporting a populist won't bite them in the ass the minute they cease to be useful to the populist. The trail of their dead is four years long. Here's the calculus: "can you benefit from an unruly mob?" The answer isn't always no. But for people who practice politics on a horizon longer than six months, the answer is usually no. Thus, the Trump administration was filled chockablock with impolitic strivers and hangers-on who have never had to convince anyone else of their viewpoint. They were all ideologues and opportunists whose goals aligned with the Trump administration until it didn't. The smart ones pulled the ripcord before they were thrown out of the plane but at the end, there was nobody. You have to be pragmatic enough to costs-benefits the "better alternatives". Politics is a game of compromise out of pure survivorship bias and those who cannot compromise cannot lead for long.