Stop me if you’ve heard this one:
You’re a politician, and you have two opponents, one more extreme than the other. They have to go through a primary to see which will run against you in the general election. Who would you prefer to win the primary? At a glance, one might think that the safest thing for the general public is to have an election contest between you and your less extreme opponent, so that you don’t have to risk the more extreme candidate getting in. On the other hand, what if the more extreme candidate is too extreme? What if they’re so extreme that people who would have supported the more moderate opponent, will now vote for you? Worse, what if you’re not sure you can actually beat your more moderate opponent? Well, for the good of you, and for the good of all those voters who you’ll definitely help when you win, you have a responsibility to try to get the more extreme opponent to win their primary, so you’ll have an easier victory.
Seems pretty straightforward, right? Polling says the voters are pretty moderate overall, so if you’re the only moderate candidate, you’re pretty much guaranteed a win!
Sometimes, you just lose because it turns out that you didn’t understand the voters as well as you thought.
Sometimes you end up helping fascism to advance.