Does Donald Trump blocking certain Twitter accounts violate First Amendment?

Even for actual public events they’ve been using “free speech zones” for a long time.

I’m a little worried I’m getting confused between what I think is and what I think ought to be:

For bringing signs I think is and ought probably align okay. They could ban all signs from an event or force everyone with signs to stand in the “signs” zone (conveniently not visible from the stage). If you said they were trampling on your write to speak they could just say the signs would block other people’s view and if you have something to say you can write them a letter.

For the issue of excluding you based on your social media posts or previous speech I think they could get away from it by citing “security” (and if you argued then they might have to make you into a security threat). That’s obviously gross, and seems like it is a free speech issue.

So I guess I agree (or partly agree?) that if the reason you are not allowed to see the president’s tweets is in retribution to your previous speech, that’s running into free speech issues.