Well, seeing as I don't give 2 fucks what someone else thinks, I'd just act like i agreed with the dude why subtly making him look like an asshole. That approach is so much more fun than just being outright assholic. Oh, and keep doing what you're doing, don't let other people feed you their propaganda. Ask him what it feels like to be a puppet spouting government bs that has been fed to the public for 30 years. And then call him a douche, light a j and leave.