I've followed Matt since 04 when he started out doing Manhunt. He's always been notoriously quiet about his politics. That said, social media over the years has revealed a little into that. I've noticed he does follow some conservative things, but also follows some liberal things as well. On a rare occasion, he would retweet something on twitter (when he used it more) that was fairly moderate.
From his old podcast with his wife, it was quite clear that he's fairly laid back on most things. It's the wife that leans more conservative (and from who she used to follow on her twitter, it's very obvious).
As for pro-gay things, his old social circle when first lived in LA was pretty much all gay/bi men. And he has 'liked' pro-gay things on instagram, including posts of a fellow celeb and his husband getting married (with other couples pics as well).