A fan subreddit might be ok, a subreddit that actively perpetuates violence and extremely large amounts of lies/false information is not ok. It would be ok if The_Donald was just a forum where people hyped up Donald Trump, but a lot of people post large amounts of false information that all the viewers soak up. I think that's really toxic.
"head chewed off with talking points" doesn't sound particularly bad (it even sounds like a form of debate!), certainly better than being banned for life in The_Donald.
Yelling != debating. You can't have a serious debate if the other side isn't listening. Some subs ban conservatives, others just let their subscribers attack them.
Go pretend to be a conservative on Reddit and see how you're treated, it might give you perspective.
Also, conservatives != donald. Real conservatives do not support donald trump, as he is not a conservative. Perhaps you are mistaken.
As a conservative if I go to /r/politics, I'll get my head chewed off with talking points and downvoted to oblivion if I try to debate anything, noone wants to listen. /r/askThe_Donald is a great place to have debates though, I wonder if there's an equivalent sub to ask liberals questions.