If I walk into a coffee shop and order a cup of coffee, I don't want the cashier to start telling me how much she hates Bush and how evil Republicans are. That's not what I'm there for. I'm there for a freaking cup of coffee so my reaction is pretty much, "I didn't get my ass out of bed at 5 and trudge down here to listen to your half-baked, parroted political blarney so why don't you STFU and get me my God damn cup of coffee?"
Hell. I'm an IT Director. I could set the Active Directory domain at my company so that everyone's home page in Internet Explorer would be Free Republic. Why not? It would only piss off half my users but, who cares? I'm the one in charge of it so it's OK, isn't it?
If your business isn't politics, you should keep your politics out of your business. It's just basic civility. And if you're going to try to parlay your fame for having a pretty voice, or being able to memorize a script and make believe that you're someone you're not, into political prowess, you better be prepared for the negative reaction of people who are paying you money to help them escape from their day-to-day drudgeries - which include politics.
Haven't they always? From Woody Guthrie to Arlo, from The Beatles to Toby Keith, musicians have expressed their views with their voices. I'm just glad I can separate their music from their madness!