"Most artist types are liberals, because they're all about feelings."
I tend to agree with you. I do know a sci-fi writer, who did write for a famous sci-fi show, and is liberal to the hilt, as were and are his associates. Their condemnation of the United States more conservative ways of life and religion were a constant target in the show, lambasts laced in and out the plot and disguised amongst symbolic images.
I hang out on the convention circuit, I know lots of writers, most are pretty liberal except when it comes to guns, they tend to like guns.
That could be Kenneth Johnson, J. Michael Straczynski, or any number of other folks. :)