If people try to crush speech they don’t like, and fringe groups are the only ones saying they support freedom, otherwise neutral people who are concerned about their rights are going to side with one of those groups.

The number of people siding with those groups will be more than zero. Support will grow and they’ll push their message farther and farther into extremism.

It’s not the first time this has happened. But each generation thinks they’re enlightened and extremism won’t take over again. Political extremists work with a grain of truth (“Look! They really ARE oppressing us”). If they were absolutely false nobody would support them.