bobdole123456's point is that monopolies aren't illegal but abuse of monopoly power is illegal (you're being downvoted because you do not explicitly address that fact).

But I actually think you raise an extremely interesting question: does pushing a political agenda using your monopoly position constitute an abuse of monopoly power?

The advent of privately controlled monopolistic forums is somewhat new. I don't think it's at all obvious how the spirit of anti-trust law should be extended in the age of platforms...

We're in new territory.