With regard to Google: personally, I don't think making content slightly less visible constitutes censorship. On a broader level, there's some content I think should be less accessible, like how gore and porn get NSFW tags, but that isn't the same as censoring it. Semantics aside, the difference here is that there's no authority figure filtering you out. You're not being shut down by reddit mods. You just have a minority opinion.

Conversations derailed

I can see why you're frustrated, but /r/conservative's solution isn't the answer. The right wing isn't well represented online, that's true. But creating platforms dedicated specifically to the right wing, in this political climate, will always be a dumpster fire railroading to extremism. The Bush-era fiscal conservatives are such a minority that you'll get flooded out by Trumpies instead of left wingers.

Honestly, I don't think most posters a place like /r/conservative attracts are interested in discussing policy, anyway. I think you'd be better off going to places discussing the specific policies you'd like to talk about - military spending, education, whatever - and participating without letting on that you're a Republican. That way, you can hold a conversation without getting into the us/them of it.

If they didn't brigade, the sub would open back up.

I doubt this. The flairing system is so conveniently easy to control. Where is the line where you become "conservative enough" to post in /r/conservative? All you have to do is revoke moderate posters' flair, slowly pushing the line back, until you have T_D 2.0. The current content of their sub encourages me to believe that's where they're headed.