If you're yelled at, boycotted, have your show canceled, or get banned from an internet community, your free speech rights aren't being violated. It's just that the people listening think you're an asshole and they're showing you the door.
I am not sure any populist politician has quite realized this power. Trump has to an extent but he has no backing from anyone in media, education, or most government employees. Now that Trump has broken so many tacit rules, I fear a charismatic leftist populist would be able to nationalize these private struggle sessions and vastly amplify his or her power.
The mob has not been a force in politics for a long time. I fear a resurgence.