WHY NEBRASKA’S NEW ABORTION LIMITS MATTER…. In Nebraska this week, Gov. Dave Heineman (R) signed a law mandating sweeping new restrictions on abortion. The state law bans most abortions mid-way through the second trimester, and was apparently intended to limit the medical practice of one man, Dr. LeRoy Carhart, who is one of the region’s only physicians to treat women in need of third-trimester abortions.

But what makes Nebraska’s new effort especially noteworthy is the basis for the new law. The state’s restrictions are predicated on the notion of “fetal pain” — a national first — which lawmakers set at 20 weeks gestation.

Amanda Marcotte considers the implications of such a measure.

Should the court defy expectations and uphold this new ban, the effect on the availability of abortions performed at or after 20 weeks would be dramatic. Most states don’t bother to restrict abortion pre-viability, because the Supreme Court precedent forbids it. Should that change, we can expect a wave of conservative states passing laws restricting abortions at 20 weeks and quite likely experimenting with other justifications that allow bans at earlier stages.

According to the Guttmacher Institute, 20 percent of abortion providers quietly offer abortions in the 20-24 week period. But the number of abortions performed after 20 weeks constitutes only 1 percent of the total, and most of that 1 percent happen before viability. Even the three remaining clinics that perform abortions after 24 weeks do so rarely.

At least some abortions after 20 weeks occur because of fetal abnormalities not discovered until after certain tests are possible. We know that women have such late surprises and humane laws should be nimble and unintimidating enough to accommodate them. But the Nebraska law does its best not to allow most medical exceptions. Under current law, the medical indications for late-term abortions include fetal abnormalities and the health, including the mental health, of the mother. The new law narrows the definition so that a doctor must be able to prove that the pregnancy could cause death or “substantial and irreversible physical impairment of a major bodily function.” The law explicitly excludes the threat of suicide as a reasonable threat of death or substantial impairment.

Several legal experts this week predicted Nebraska’s new statute will not fare well in the courts. Something to keep an eye on.

Our ideas can save democracy... But we need your help! Donate Now!

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.