If the law is allowed to go into effect it could shutter all but about 10 clinics in the state.
Texas Solicitor General Scott Keller faced a sustained attack from the three female justices on the bench joined by Justice Stephen Breyer, who questioned him about the impact the law would have on poor women living far from the remaining clinics, the medical necessity of the law and the generally low risk of the abortion procedure.
Wednesday's oral arguments addressed the most significant abortion case in two decades and is the first major controversial case the court has handled since the death last month of Justice Antonin Scalia.
Justice Anthony Kennedy, whose vote will be crucial in this closely divided case, asked questions of both sides. At one point he suggested that the Court might remand the case back to the lower court to develop a fuller record.
The fact there are only eight justices raises the possibility that the court could end up in a 4-4 split -- which would allow the Texas law to take effect but not set a national precedent. If the court is split, justices could also ask for re-argument next term.
"If the questioning is any indication, there are three solid votes to uphold the Texas law, four to strike it down and Justice Kennedy is in the middle," said CNN legal contributor Stephen I. Vladeck. "If Kennedy is unwilling to invalidate the law at this stage, the question becomes whether any of the justices who were will join him in a narrow remand."
Justice Ruth Bader Ginsburg -- the leader of the Court's liberal wing -- asked several sharp questions of Keller, who contended that all the metropolitan areas in Texas would still have open clinics under the law.
"How many women are located over 100 miles from the nearest clinic?" Ginsburg pressed.
When Keller conceded there were women in that category, he added some could access a clinic in New Mexico, Ginsburg pounced.
She pointed out that the New Mexico facility has neither the admitting privileges provision nor the requirement to upgrade the abortion clinics outlined in the Texas law.
"If your argument is right, then New Mexico is not an available way out," she said.
She also brought up whether it would be necessary to upgrade clinics to meet higher surgical standards when abortions are often performed through medication.
"What is the benefit of having an ambulatory surgical center to take two pills when there's not a surgical procedure at all involved?" she asked.
Justice Elena Kagan supplied statistics that she said illustrated how many women would be impacted by living over 100 miles from the clinic.
"The statistics that I gleaned from the record were that 900,000 women live further than 150 miles from a provider," she said.
Sotomayor questioned whether -- even if the new requirements produced "the slightest health improvement" -- it was enough "to burden the lives of a million women?"
Kennedy expressed some concern that the law would increase the number of surgical procedures as opposed to medical procedures and that that "may not be medically wise."
While the comment suggested some hesitation about the law, earlier in arguments Kennedy suggested that the court might remand the case to learn more about issues such as the capacity of the remaining clinics to handle an increased number of abortions.
"Would it be A) proper and B) helpful for this court to remand for further findings on clinic capacity?" he said.
If the court were to remand the case, it might delay an opinion on the merits.
Alito at times also suggested discomfort with the record below.
"There is no evidence of the actual capacity of these clinics," he said. "Why wasn't that put in" to the record?
Later in arguments he cited an amicus brief that mentioned that some clinics had been cited for "appalling violations" when they were inspected, suggesting a reason for the Texas law.
Impact of Texas law
Supporters of the law argue that it is meant to protect women's health, but opponents say it has nothing to do with health and safety but is instead a disguised attempt to end abortion. Similar laws enacted in other states are percolating through the lower courts.
Lawyers for the Center for Reproductive Rights, representing Texas clinics such as Whole Woman's Health Center, argue that the requirements in the law do not enhance abortion safety but instead will make it harder for women to end a pregnancy by reducing their access to the clinics.
"The impact of these closures has been dire, delaying many women -- and preventing others -- from obtaining a legal abortion," argued Stephanie Toti, a lawyer for the center, in court papers. "This, in turn, has led to an increase in abortions later in pregnancy and in illegal abortions."
Other groups, such as the American College of Obstetricians and Gynecologists and the American Medical Association, have weighed in against the Texas law -- called H.B. 2 -- arguing it lacks valid medical justification.
The medical groups say there is no need to upgrade their facilities. "Surgical abortions simply do not require the size, layout or equipment of a full operating theater," their lawyers argue in court papers. They also stress that local admitting privileges for abortion providers are unnecessary for reasons have nothing to do with a clinician's competence, noting that such privileges are often given to clinicians who admit a certain number of patients.
The law applies to any abortion clinic that provides more than 50 abortions a year. Lawyers for the clinics say that the vast majority of women in Texas receive abortion services at such clinics.
Before the law, there were more than 40 facilities in the state. That number was cut in half once other provisions of the law went into effect. If the court were to rule in favor of Texas, there would be about 10 clinics in the state.
Toti argues that wait times in some areas are now lengthy and that the law violates court precedent by placing a substantial obstacle in the path of women seeking an abortion.
She says court precedent requires "meaningful judicial review to prevent unjustified intrusions on a woman's constitutionally protected liberty."
Texas counters that the law was passed in response to the Kermit Gosnell scandal. The Pennsylvania man was convicted in 2013 of first-degree murder for killing babies that were born alive in his clinic.
Keller argued in court papers that if the court upholds the law, an abortion clinic "will remain open in each area where one will close, meaning that over 90% of Texas women of reproductive age will live within 150 miles of an open abortion clinic."
Keller says that challengers to the law want the court to serve as a medical board "by second guessing legislative judgments supported by medical evidence" and that the court has "made clear that such decisions belong to legislatures."
Friend of the court briefs
Being the first major abortion case in years, the case has seen a high number of friend of the court briefs, including many from women on both sides of the issue who have had abortions.
Former Texas State Sen. Wendy Davis, a Democrat who filibustered a similar version of the law for nearly 13 hours in 2013, signed one brief detailing her experience in having to terminate two pregnancies for health reasons. Another brief was filed by several women who chose to have an abortion and "strongly believe that the right to access an abortion was and is crucial to their and every woman's ability to define her own existence."
Actress Amy Brenneman, among others, signed the brief detailing the abortion she had in 1986 when she was a 21-year-old junior at Harvard. The brief says that her access to an abortion "when she was not ready for motherhood" allowed her to "avoid the depression that would have accompanied the derailment of her life plans" and enabled her to "exercise sovereignty over her body." She later went on to have two children.
On the other side is an amicus brief filed by the Justice Foundation on behalf of 3,348 women across the country who say they have been injured physically or psychologically by their abortions. Approximately 600 to 700 of women who signed the brief are from Texas or had abortions in the state.
"The abortion industry needs strict, rational, but serious regulation," Kathleen Cassidy Goodman, a lawyer for the foundation argues in court papers. An appendix to the brief includes the names of the women and in some instances the names they chose for their aborted children. Goodman argues that the Supreme Court should defer to the "proper legislative process."
Texas is also supported by former abortion providers who argue that the law "provides common sense health and safety regulations to protect women."
They point to Gosnell's clinic that was described by one district attorney as a "house of horrors."