"if you're worried about the slippery slope that comes from restricting nazi speech, why aren't you worried about the slippery slope that comes from letting nazis speak"
That's pithy and I'm definitely stealing it
From the first segment, "Against Free Speech Absolutism", of this podcast:
https://www.wnycstudios.org/podcasts/otm/episodes/on-the-media-sticks-and-stones