I think it’s clear they were booing him because he was gay. Listen to teh boos when he says he’s gay and tells his story, and listen to the rousing ovation that Santorum gets when he talks about how allowing openly gay people to serve amounts to special privileges. These to me weren’t anti military intervention Ron Paul fans booing a soldier, these were homophobic assholes booing a man because he’s gay and their delusional thought that gays in the military will destroy the military. And in grudging defense of Ron Paul and his supporters who I make no secret of my disliking, the latter tend to be less homophobic than the others in my observation. Maybe it’s because Paul supporters are by and large a younger crowd, I dunno.