Here's what I think, if anyone cares.

I think that Jon's a redditor, that he ended up, through that, with the Gamergate crowd, and that his political outbursts can be explained by this. He's been following a characteristic trajectory for a while now.

Stage one is standard reddit fare. There's a Grumps video where Arin mentions Jesus, and Jon responds with something like 'you mean the one that I don't believe in?' Looking back, it seems a little strange, until you remember that this was back when the atheism subreddit was a default, and that it had a constant crusade going to enlighten the world.

Another popular reddit view is the sanctity of humor, that humor shouldn't be limited by what offends. People sometimes call it being anti-PC, but I believe that's a more recent usage of the term which implies more strongly a political statement. I actually mostly agree with this view, but it's also a popular reddit opinion, and Jon has expressed it on Grumps multiple times.

Stage Two was Gamergate. The movement grew on Reddit, and the community was made up of people with the persecution complex of the ratheist and the righteousness of the anti-censor. Not much obscure evidence here, Jon was known to be a supporter. I do think it, or possibly something a little afterwards related to it, was probably what split up the Grumps.

Stage three was most prominently signalled by the Breitbart interview. Breitbart, as a connection, is a favored news source of gators (and yeah, they still exist). Stage three is further evidenced by the recent political tweets.

I disagree with him, as you can tell. I think that although by stage three he's outgrown getting his news and views exclusively from Reddit, he's never lost that attitude he originally picked up from it. He's still getting outraged at the same bogeymen, looking for reasons to reinforce those negative views instead of reasons to change them. Always trying to get in some new 'gotcha' against whoever's making noise.

I'm both disappointed and sorry for him. I'll still watch his videos, for now, since I can block the ads, but if he actually makes a vlog, depending on the content I might unsubscribe just in the hope that he reconsiders his views. I know he can be better than this.

Edit: People are still reading this, so I have to make a correction, Gamergate didn't happen until a year after the Grumps split, so it probably wasn't the cause. At the risk of making another temporal blunder, I think TumblrInAction was active around that time, and it originated a lot of similar ideas, so I can switch the suspected cause there.