By asking them to restrict speech.
They didn't force them, so it's ok, That's your argument, must I make it for you?
For 1, Twitter, et al, are not "Free Speech" platforms. Just like this forum is not a free speech platform.
For 2, asking is not restricting.
And
asking the media is a very, very common practice.
Now if both of the administrations, Republican and Democrat said, post/remove those tweets
or else...
Now that's a different story. But I haven't seen the "or else" restricting bit. Maybe it's there, but I haven't seen it. Do you think you getting banned here a gazillion times is a violation of your 1st amendment rights?