About a month ago, I gave my cousin a ride to Georgia State University in downtown Atlanta. After I dropped him off, I proceeded towards the capital building and came across a war protest. It wasn't very big, probably not even forty people. They were carrying mock coffins. They were all just like the guy you described, middle-aged to elderly, but still dressing like kids. Even though it was right next to a university, I did not see one young person among them. I thought that was really funny.
During my years in graduate school at U.C. Berkeley, a group calling itself (as I recall) the "Soviet-American Friendship Committee" would show up on campus periodically. They were all white-haired men and women, relics from the 1930s, who remained true believers in Communism. They would pass out a selection of books and pamphlets by the likes of Marx, Lenin, and Stalin. They had learned nothing from the bloody record of Communism. As mother says, there is no fool like an old fool.