Earlier quoted context omitted.
Seems like having the president attack Twitter for their speech (adding extra speech that suggests that some shared information is disputed) is the actual violation of Free Speech. The First Amendment says that the federal government can't stifle free speech, which seems like what is happening here.
Bedhead's point still stands in isolation from this week's bullshit, though. Trump will be on to some other highly divisive circus act next week. The question of whether Twitter is a public square will persist.
Arguably twitter isn’t even that powerful except that the president uses it as an official communications platform. Before this current administration, Twitter was circling the drain. It was an afterthought in modern social media. The president pretty much singlehandedly made twitter as important as they are today. If the president doesn’t like twitters TOS he could switch to Facebook and have an even greater reach than he does today. So it’s hard to argue that twitter is actually the problem, but if they are, the easy answer is stop using their platform and switch to a competitor.