Part of what makes authoritarian behavior so dangerous is that they don't need a majority to cause a lot of damage, just a very sizable group. You want to stamp it out quickly before a lot of damage is done, and "fighting fascism with the truth" generally takes time on a generational scale.
It is worth noting that the election before Hitler was made chancellor, the Nazis actually lost 14% of their seats in the Reichstag, yet they were still powerful enough to eventually come to power.
You're playing very fast and loose with terminology here. Fascism is a form of authoritarianism, but not all authoritarianism is fascism. Censorship is authoritarian. We were talking about fascists before you joined the conversation, but if you're going to swap the terms here and start worrying about authoritarianism, neither side is innocent there, and taking a "stamp it out quickly" stance is inherently an authoritarian position, not an anti-authoritarian position.
> It is worth noting that the election before Hitler was made chancellor, the Nazis actually lost 14% of their seats in the Reichstag, yet they were still powerful enough to eventually come to power.
Yes, but that's a fairly useless fact if you don't have any explanation for why that happened.
Change isn't a popularity contest. If King changed views on black voting rights from 20% for to 40% for, that's a pretty massive change.