I am a pastor. My job is to talk. I give a 15-20 minute "speech" at least once a week, plus at least an hour or two of classes in which I lead the discussion. Often the subject matter can run close to the line between theology and politics. But I actually am a minister of the gospel, and see that as my calling--unlike Jesse Jackson, Al Sharpton, Jeremiah Wright, and Michael Pfleger. So I do not abuse my "bully pulpit" (literally).
Now, I tell my parishioners, if we are at the cafe, talking over lunch, and I take off my clerical collar, then I may discuss my personal views on political candidates, if that's what you want to talk about. But then I am speaking only as a fellow citizen, not as your pastor.
My approach is similar to yours. I leave my politics behind when at work. I’ve begged out of the arguments that have developed at the workplace knowing them to be potential disasters in the making.
When a bunch of us went to out to lunch I answered a question about the “0”ne with an unflattering (but accurate) opinion. Later in the office one of my co-workers wanted to extend the debate and I demurred, telling him that I don’t talk politics at work.
He was dissappointed because it is a very liberal office and he wanted more anti-obama voices to be heard.
I understand his viewpoint, but professional ethics take precedent.