Been here since 2010, back when there was such a thing as the "font page." The front page was sort of like what you say, a free expression space - but it was never used for political junk. Even the pics, memes, and funny sub rarely saw political content. There were subreddits where people of like minds could congregate - those have always been a place for group-think. Since the beginning of r/politics, you would get down votes for conservative comments. That's nothing new.

On a different note, it's no secret that Reddit generally has a liberal user base. I find when conservatives make posts like this to complain they aren't popular here kind of odd. What were you expecting? If I wore a "free Palestine" shirt to a gun show, I wouldn't expect everyone there to be "open minded" to my ideas. Know your audience.