Rival legal teams are girding for court battles over the coming months on laws enacted in Arkansas and North Dakota that would impose the nation's toughest bans on abortion.
From both sides, attorneys agree that the laws represent an unprecedented frontal assault on the Supreme Court's 1973 Roe versus Wade decision that established a nationwide right to abortion.
The Arkansas law would ban most abortions from the 12th week of pregnancy onward. North Dakota's law would ban abortions as early as six weeks into a pregnancy, when a fetal heartbeat can first be detected.
Abortion-rights advocates will challenge both measures, contending they violate the Roe ruling that legalized abortion until a fetus could survive outside the womb. A fetus is generally considered viable at 22 to 24 weeks.