You want seriously divisive?
Try this:
The pro-life movement decides that it is going to use low-level but widespread violence/intimidation coupled with wholesale jury nullification (i.e., it instructs its members, bonus points if the Catholic church says this is a religious duty, to find anyone innocent in such cases) to acquit all of their perpetrators and proxys to get its way. This results in a cycle of escalation between the establishment and the movement. How does the justice apparatus respond, for instance, when large numbers of obviously 'guilty' defendants are acquitted or have the juries hang? Overreact and you're likely to have the beginnings of a civil war on your hands.