There is, of course, a lot of discussion regarding yesterday's murder of George Tiller, who made a living performing late-term abortions in Kansas. Although no one really knows yet, everyone is assuming the perpetrator is a prolife activist. That is, of course, a reasonable assumption.
Killing babies for a living has a way of making people think less of you.
There are a lot of ironies in this case, one being why a person who presumes to be an activist in an organization whose purpose is to save lives would act to take a life. But the world is full of ironies. I once saw a talk show on which the guest, a pacifist, got so aggravated at the host that he took a swing at him.
Another, perhaps more significant irony is that the very utilitarian logic that is the only rationale for such an action ("If I kill the abortion doctor, I will save lives") is the same logic that leads people like George Tiller to do what they do. But you can't fight utilitarianism with utilitarianism. It only breeds more utilitarianism.
Maybe there is a utilitarian argument for eliminating utilitarians, but only a utilitarian would be convinced by it.
Obviously the murder will be turned to the propaganda advantage pro-abortion groups. They will portray it as an example of where the prolife position leads, when, in fact, such actions are blatant violations of everything the movement stands for. That will give them the rhetorical advantage and benefit their case.
But how can you blame them? They're utilitarians. That's what they do.