Just let them gain power for a short time and people will see their true face and not vote for them again. Worked in Germany. The NSDAP never got a majority of votes.
And allow them to get their message out on every possible platform all the time. This will not normalize hate speech and recruit members at all but will make people will see they are evil and ignore at them until they evaporate.
Did you know that the leader of the NSDAP took his life once he realized that he has failed? While this is a sad fate of an individual, it tells alot about how people can be chastened not by silencing them but quite the opposite way.
Even better - the leader of the NSDAP killed Hitler! Truly a hero of democracy 🫡