You make a valid point, although we don't register by political party, I'd tell anyone who asked, that I am independent. That said, I've never voted for a democrat and no liberals with the exception of McCain.
Here in Illinois, our state has just elected a so called "republican" to fill the U.S. Senate seat. He won without my vote because he is the ultra liberal POS, Mark Kirk. I voted for the Libertarian, Mike Labno, the only candidate on the ballot who was pro life. The first time ever for me voting Libertarian by the way. Labno received just over 2% of the vote.
I am an Independent myself, way to the right of Republicans.