As with any other business, a T's politics may be a turn off for certain clients, and that's a chance they take when they are public about their opinions. I don't think they have an ethical obligation to stay silent, although I don't think they have an ethical obligation to speak out, either.

I believe there is a rule against "diagnosing" public figures but saying someone "meets the criteria" is a bit different from diagnosing. Plus we see so much of these people in the media sometimes it's clear they do meet some criteria...

Personally I mute people on social media who are constantly reposting political stuff, just in general. Even if I agree with them it gets very repetitive.