Well, it's how left-wing movements burn out, anyway. The far-right has already succeeded in overrunning one of America's two major political parties, and that comes with a sort of permanent legitimacy akin to being in the UN Security Council. No matter how evil you are, you'll always have a seat at the table. And it doesn't seem to have cost them much in the way of votes, either, which to me means roughly half the American voting population is fully on board with their extremism.