It's OK to have different views from other people. But the minute he started calling you names, and deliberately winding you up, he ceased to be your friend. He is a world-class, um, lower orifice of the digestive tract (trying to avoid profanity there) and your life would be happier without him in it. No matter what the political leaning, no friend would treat you that way.

If he's that lonely, he'll learn that if he wants to keep you as a friend, he'll start treating you with respect.