Actually.... I bring up politics on a first date.
In engineering (as I am sure you know) there is the idea of "fail fast". If something is going to go wrong, you want it to go wrong before you have wasted time and resources (this is very important in designing web applications). So, if someone is going to disapprove of my politics, I would like to know on the first date.
The purpose of a first date is to determine if the two of you can get along together. If she storms out in disgust muttering under her breath about what an asshole I am, that is a success (that doesn't happen as often as you might expect).