Three of the four examples I gave were anti trump because they happened to be at the top of my blocked list, probably because they were the first posts I was annoyed by. I also mentioned r/trumpforpresident.

And in my opinion, your third paragrah applies even stronger to heavily moderated subreddits (/r/the_donald anyone?) because dissenting opinions are just removed. Unless this is super public and regularly discussed, oftentimes I find that it's easy to forget about and fall into the trap of thinking that everyone feels a certain way. Sure at first it is right in the front of your mind but eventually it fades away (at least, in my experience).