From The Murderer-Martyr Syndrome:
The president of the Kansas Coalition for Life, Mark Gietzen, says Roeder was "incredibly stupid" if he thought killing Tiller would be "a pro-life act." Geitzen says the slaying has instead turned Tiller "into a martyr" while doing nothing to stop abortion.
First, there aren't any people among whom Tiller can become a martyr. Even assuming anyone tries to commemorate him with any dedication, he will be forgotten in a generation, for they will undoubtedly either kill their children or just not have any in the first place.
Second, nothing is what Republican presidents and, apparently, presidents of the Kansas Coalition for Life do. Aside from the occasional sidewalk conversion wherein a local christian or two manage to get a pregnant woman to turn away from the abortion clinic, by what metric do pro-life activists measure their success? Abortion continues, and though pro-life political forces have made good inroads in certain states, Obama's administration is busy proving how illusory such gains can be.
Third, I'd hold off on the 'incredibly stupid' characterization. We may bestow such a characterization at a later date, when we know more; indeed, if he felt justified doing it now, why didn't he feel justified when Bush was in office? Does Republican lip-service have that much effect? On the other hand, we may find the man is not stupid, but rather has valued certain things, like his own life, a bit differently from the way we do. I realize this may be a distinction largely lost in America, but it is important nonetheless.
Finally, any pro-lifer wanting to discuss this issue should speak about justice, and how justice is not being done in the courts, and how justice is not the sort of thing we should allow to be undone, because if it is left undone vigilantism is exactly the sort of thing that happens.