I don't normally like to let someone who seems mostly troll-like to frame the discussion, but in this case I'll play along.
At this point in time, I don't believe it's a constitutional issue. From the perspective of freedom, I would probably agree with you, because I believe a company can do what it wants to, as long as it's not violating the law. And in this example, they're not violating the law.
From a free speech perspective, anyone who believes in the 1st amendment, should at a minimum, be very concerned when any speech is censored by any media outlet of the size and influence of Twitter and Facebook (just two examples.) Particularly when it's censored with such an obvious bias.
I don't usually like to rely on wikipedia, but in this case it is the expedient way to make a point.
https://en.wikipedia.org/wiki/Section_230
"At its core, Section 230(c)(1) provides immunity from liability for providers and users of an "interactive computer service" who publish information provided by third-party users:"
These companies are well beyond being useful platforms for connecting people, imo. Facebook is so far beyond being a nice little place where Grandma in Illinois can keep up with the kids and grandkids in Florida, that there's no legitimate way to deny that they are on a par with other "media" outlets or platforms, like the Washington Post or the New York Times.
Point being, imo they should not be exempt from liability and they should not be allowed to censor, given their position as media giants. Is that straight forward and clear enough for you?