On the other hand, you could just allow free speech and expression, a strategy that has worked extremely well in western civilization for at least the last 500 years.

For instance, I have no problem with letting Nazis present their views - it only makes them look as ridiculous as they actually are, and tyranny by Nazis is no better than tyranny by Socialists/Communists, so reasonable people who are not ignorant of history should strongly oppose both. (Although, arguably, the Nazis were far less effective at killing millions of people than the Communists were...)