What a loser. I probably align more with him than you politically, but I don't go around berating internship candidates about it, it's no way for an adult to behave whatever your politics.

Whenever I have shitty experience like that I always think of the James Bond movie Quantum of Solice, there's some part where somebody doesn't deliver and the bad guy loses out, and upon being told he lost something valuable, he says "not as valuable as knowing who to trust". Like you say, it was a bad experience but actually the best possible information you could have gotten.