On Tuesday a panel of judges of the U.S. Ninth Circuit Court of Appeals permanently struck down an Arizona law banning all abortions at 20 weeks, calling the extreme measure “unconstitutional under an unbroken stream of Supreme Court authority, beginning with Roe and ending with Gonzales.”

The state law, which had been scheduled to take effect on August 2, 2012, would have banned all abortions at 20 weeks after a woman’s last menstrual period (LMP) without any exceptions for a pregnant woman’s life or health unless she is experiencing a dire and possibly life-threatening emergency. The law, HB 2036, would have banned abortion earlier in a pregnancy than similar laws recently enacted across the country and at a critical point when many women undergo prenatal testing to evaluate their own health and the status of their pregnancy.

The Center for Reproductive Rights (CRR) and the American Civil Liberties Union (ACLU) filed a lawsuit, Paul A. Isaacson, M.D. v. Tom Horne, Attorney General of Arizona, in July 2012 in the U.S. District Court of Arizona, on behalf of three physicians who perform abortions and serve women with high-risk pregnancies—arguing that the Arizona law violates the U.S. Constitution by banning pre-viability abortions. After a federal district court judge denied a request to temporarily block the law and issued a final ruling upholding the statute, CRR and ACLU appealed to the Ninth Circuit Court of Appeals, which immediately blocked the law from taking effect while it deliberated the appeal of the District Court’s decision.

The opinion that followed was a forceful reaffirmation of a woman’s right to control her pregnancy pre-viability. The 44-page order repudiates much of the reasoning used by U.S. District Judge James Teilborg in originally ruling the law constitutional, including his parsing of the difference between a “ban” and a “regulation” and his assertion that because some pre-viability abortions would theoretically remain available under the law that it did not violate Roe. “The challenged Arizona statute’s medical emergency exception does not transform the law from a prohibition on abortion into a regulation of abortion procedure,” the opinion states. “Allowing a physician to decide if abortion is medically necessary is not the same as allowing a woman to decide whether to carry her own pregnancy to term. Moreover, regulations involve limitations as to the mode and manner of abortion, not preclusions of the choice to terminate a pregnancy altogether.”

Importantly, the Ninth Circuit rejected outright the argument that the federal courts are not bound to consider viability as the point at which to determine whether a state can pass a restriction that creates an undue burden on a woman’s right to choose. In other words, one of the goals of the Arizona ban was to test the strength of viability as a cut-off point in banning, or severely restricting, access to abortions. This is important as anti-abortion activists pursue increasingly restrictive laws on abortion access based on blurring science on issues like so-called fetal pain as is the case here.

But, in this ruling, the Ninth Circuit said clearly that pre-viability bans run contrary to precedent and are unconstitutional. “Roe identified fetal viability as the earliest point in the pregnancy when the state’s interest becomes sufficiently compelling to justify not just regulation of the abortion procedure, but proscription of abortion unless necessary to preserve the life or health of the mother,” the court wrote. “Since Roe, the Supreme Court and lower federal courts have repeated over and over again that viability remains the fulcrum of balance between a pregnant woman’s right to control her body and the state’s interest in preventing her from undergoing an abortion.”

On the issue of whether or not Arizona’s pre-viability ban would survive because of its narrow exception for the life and health of the pregnant woman, the court forcefully disagreed. “The presence of a medical exception does not make an otherwise impermissible prohibition constitutional. The adequacy of the medical exception has no bearing on whether the prohibition is permissible in the first place. The twenty-week law is unconstitutional because it bans abortion at a pre-viability stage of pregnancy; no health exception, no matter how broad, could save it.”

Nancy Northup, president and CEO of the Center for Reproductive Rights, said the following in a statement: “Today’s decision is a huge victory in the fight to protect women’s fundamental reproductive rights, and it should send a clear message to anti-choice politicians that their attempts to deprive pregnant women of critical health care are clearly unconstitutional and will not hold up in court.”

Attorneys for the ACLU who were also involved in the legal challenged were similarly pleased with the ruling. “We’re glad the court has reaffirmed that states cannot place unlawful burdens on a woman’s right to access safe reproductive health care,” said Talcott Camp, deputy director of the ACLU Reproductive Freedom Project. “Politicians do not have the right to interfere in serious and personal decisions that should only be made by a woman with the help of her family and her doctor. The ban would have forced a physician caring for a woman with a high-risk pregnancy to wait until her condition poses an immediate threat of death or major medical damage before offering her the care she needs. The ban also contained no exceptions for a woman who learns her fetus will not survive after birth.”

“Lawmakers cannot impose their personal ideologies on the women of Arizona,” said Dan Pochoda, legal director with the ACLU of Arizona. “This law endangered women’s health and was knowingly passed by the Arizona legislature despite clearly violating established constitutional requirements.”

This is the second opinion from the Ninth Circuit to unequivocally support abortion rights. Last year the Ninth Circuit Court of Appeals ruled states can’t prosecute pregnant women for “self-abortion” in the cask of Jenni Lynn McCormack who purchased medication online to terminate her pregnancy.

The ruling is not binding nationally, but covers the states of Arizona, California, Nevada, Hawaii, Oregon, Washington, Idaho, and Montana. And since supporters of the measure, including Arizona Attorney General Tom Horne, have made it clear the law is designed specifically to prompt the Supreme Court to take up and reverse Roe v. Wade, there’s every reason to believe supporters will appeal the ruling. In the meantime, though, the decision represents a significant victory for women, doctors, and public health and a defeat for those legislating religious extremism under the pretense of “protecting” women.