But he's also a social activist. Or does he just like supporting commie dictators? And why? Because he likes power, or does he believe that communism champions the "little" guy?
I don't see Penn as an 8 because not enough of his life is devoted to 8-like activities. So I looked up some tritypes on Wikipedia. At first I thought "Reformer" (type 1) but none of those tritype titles make sense for Penn. But then I saw this:
368, 683, 836 The Justice Fighter
This contains 8, but I don't put it in first position. I agree there is an 8-ness quality to him. So that leaves 368 or 683. I'll go with 683, so he's a 6, probably 6w5 (Hitler's type).