Check out the thread on Brian's Red Bull Music Academy session. During that lengthy interview (which is linked in that thread), Brian explains, among other things, his view that people should support the candidate that will kill the least amount of people. He also expresses bewilderment over Rick Santorum's desire to "ban porno." These comments were all tongue in cheek, mind you, but I don't think you'll find much in terms of political advocacy by the band.
EDIT: Here's the link http://vimeo.com/39788008