This happens to me at work, so I know what you're saying. We have an upstart yuppie type young man in our dept., who runs his mouth constantly. He's an obnoxious, liberal Michael Moore fan, so you can imagine the garbage that comes from his mouth.
I try to be professional, and tune him out, but a few times I've voiced my opinion, which is not good in a work setting. However, the words come out of my mouth before I even realize what I'm saying.
I guess maybe I need a muzzle?...:)
Oh boy work was a dream this year. I didn't get into any debates about kwanzaa and I didn't get called into the office with any complaints.