Free speech absolutest here.
It’s simple, if someone says something dumb, you let them :) then you combat them with a sound argument. if the facts and evidence are on your side, you still may not convince your opponent, however you have the chance to change the mind and bring onlookers to your side.
By silencing speech, expression, or just people you do not like from any platform, you become the authoritarian. All anyone watching will see is that you silenced someone, shut down the discussion, this is not how you change minds. It also suggests that the one silencing the other, may not have facts and evidence on their side, because if they did they should have no reason to silence the speech.
And remember, not all things always black and white, good and bad, left or right. You may think you got your ducks in a row, but you have to be prepared to lose an argument as well, and when you do loose one, you need to be prepared to adjust your views on the subject. there is to much stubbornness around now days.
And consider what happens to this person when you silence them. They move to another platform, where they can speak freely among others whom have also been silenced. they become part of the underground echo chamber where their misinformation, or bad opinions grow and evolve, unchallenged by anyone else. The more the left censors and moves further left, the more regular people will end up in these places and become indoctrinated. and eventually the pendulum swings to the other side.
TL;DR best weapon against hate speech is more speech.