Bah, whatever.
If you need the class I'd keep it; point out to him - in front of class - that he's the professor. He's in charge. He doesn't need to yell to prove a point, people uncomfortable in their position yell.
If he wants to have an argument about the NRA, he should seek out someone who is on equal footing to have it and not a student in a classroom where he controls the discussion. A conversation between students is a debate, he wants to be a bully, so unless he enjoys being a bully he ought to cease yelling at you and leave you alone.
At least, that's how I approached such dynamics.
I was mature enough by the time I finally went off to college that I didn't feel the need to argue with professors who got pleasure out of abusing the students over their views. I'd never argue their position at all. I'd just call 'em out as bullies; shamed them for it; and told them to leave me alone.