Pro-Life activists have essentially protested peacefully for decades. So I'm not sure where you're coming up with this. Are there extremists? Sure. Are there extremists on the Pro-Choice side as well? Sure...
But for the life of me, I'm not sure how anyone who thinks taking the life of a human being or a fetus that will become a human being is a right can take the high road on this issue. Using contraception is an easy thing to do if you're going to have sex. Can accidents happen? Sure. But the fact that 45% of abortions that take place happen with someone who has already had an abortion, tells me that this isn't about protecting someone who made a mistake. It's about protecting those who use it as a means of doing whatever they want, whenever they want, and having no respect for life...