What makes someone a racist?

In responding to a caller to his radio show who claimed that if we didn't have abortion we would have more people paying into social security, Bill Bennett in knocking down that line of argument used the opposite side of the coin and said you could lower crime rate if all black babies were aborted. He immediately disavowed that idea as morally reprehensible and went on to explain that abortion should be opposed purely on its own. Everyone knows what happened next. He was denounced as a racist by a bunch of people who refused to hear a word he said except the one sentence. Bennett gave a speech where he defended himself from those charges. The key paragraph to me was this one:

All of this work means nothing to those critics. Because when I broached the sensitive topics of abortion, race, and crime, my comments became the subject of dishonest and selective editing, in order not to further a conversation, but to stop one – to put a hit on me, to take me out. Well, I’m not going. They’ve tried before. That’s not the point.

Since the 1960's I believe race relations have improved dramatically on an individual basis. However, societally relations have regressed to the point where any mention of race end a conversation rather than advancing the conversation. Most people are afraid of openly discussing matter which involve race for fear of being branded a racist.