Exactly. A private company is not beholden to the Constitution of the US. (COTUS)
But the U.S. government is.
And while, the facts need to be developed and be established, there are troublesome allegations with increasing supporting evidence that the Department of Justice of was using its powers to influence both Twitter and Facebook to make decisions that were helpful to the Clinton campaign.
I am not going to try the case here. Things are still in progress but even without getting to Twitter, Zuckerberg directly testified under oath before Congress that they were in regular contact with the Justice Department which was telling them that the Hunter Laptop was bogus Russian disinformation. EXCEPT......there is a pantload of evidence, and growing every day that the Justice Department knew it was legit and that they had also used their powers backchannel to get CNN, The Washington Post, the New York Times etc to repeat the mantra that it was Russian disinformation.
MORE TO COME.