I went to a bunch of marches in New York and Washington, and you know I believe in the cause, but to march with those people takes a lot of compromise on my end.
I'd be curious to find out, but I don't think people in the entertainment industry are proportionally more or less serious politically than anyone in the landscaping industry.
As for Tenacious D, of course it could work as a full length movie; all it requires is a great writer and great director with an ability to think outside of conventional film comedy.
In New York there isn't that weird palpable competitive thing where it's friendly but everyone isn't trying to top one another with jokes when you're just hanging around.