I have a rather long litany of people to start commenting on. One of my best examples for Jimson2 was already posted, and by a Junior Member no less. Seeing that it struck me how much more effective and telling this will be if more of us Constant Readers demonstrate the wide variety of political stripes held by King's characters. Thus, I'm only going to do one at a time so as to allow other people to jump in with their favorites.
My next one, goes out to Jimson2 because of his idea that Mr. King always puts Republicans forward in a negative light. Jimson2 went on to suggest that Mr. King should be more neutral. Okay. Here comes one for you...
Greg Stillson, the psychopathic politician from The Dead Zone, is an Independent. He is neither Democrat or Republican. Clearly if Mr. King had an agenda, he could have made Stillson a Republican couldn't he? Instead, Mr. King created a populist politician who showed the public one face and others a horrible one in private.
I figured I'd start with a neutral example (like you seem to yearn for) first.