If you're racist when angry, you're a racist all the time!
Tami says it succinctly and well on Racialicious. Some people, including those that I've been friends with, seem to think that racism or any other prejudice that comes out in anger represents a deviation from their normal character. However, I agree with Tami that pressure shows what a person is truly made of. If racism comes out of you when you are angry, you have shown yourself to be a true racist. No ifs, ands or protestations.