twitter, google, and facebook all receive immunity from any legal liability from whatever a 3rd party user posts on their platform via section 230 of the United States Communications Decency Act - which means they have no real justification for their little censorship sprees.
I sometimes wonder if these companies should be reclassified as public utilities like telephone service or electricity. They have become a part of the public square and everyday life for millions of Americans. I think this would make it more difficult for them to arbitrarily censor- with no rhyme or reason- which is what they are doing right now. Telephone company can't ban you from using the telephone just because they don't like what you're saying. Should apply to these platforms as well, I think.