I’m pretty sure Mortenson is a bit of a Lefty, I remember him paying a visit to Cindy Sheehan when she was protesting Bush jr. He also starred in the Lefty movie Mr Fantastic.

edit: to clarify, his visit to Sheehan is not libshit. Sheehan was a vocal supporter of the Pink Tide in Latin America, especially Hugo Chavez, Liberals hated her for that.