From what I saw in movie "Home of the Brave" he seemed quite Republican. Now yes, that is just a movie but I cant see any Hollywood lefty ever starring in a role which seemed to support the war, especially the troops. It was a great film. The part that showed that Samuel L Jackson was a Repuplican was when he was talking to his son (in the movie), who was furious we were at war. So no 100% certainty, but I would have to say Republican.