They fight for the unborn fetus, they have a great amount of support. These terrorists are the single most dangerous threat to the national security of the United States since the Black Panthers terrorist group. They have a large supportive group that are pro-life. The supportive group is what makes a terrorist group popular and active. Whether you like it or not, if you're pro-life like me, you belong to the supportive level of the terrorist group.
Abortion is the most controversial issue the USA has ever seen.
If not handled correctly by the FBI, ATF, etc., it could get out of control and wind up in armed revolution, forcing the government to suspend civil rights and liberties. Since everyone and their dog has guns in this country, it'll be a bloodbath from hell if it ever comes to pass.