IN THEIR four-decade fight against Roe v Wade, the Supreme Court ruling of 1973 that recognised a right to abortion, pro-lifers have taken several tacks. One is to curtail the period during which women may end their pregnancies. Another is to ban particularly grisly-sounding techniques like “partial-birth” abortion. Recently, opponents of Roe have been waging a regulatory war of attrition that makes abortion harder and harder to obtain. On March 2nd, a Supreme Court diminished by the loss of Antonin Scalia, the conservative justice who died in February, asked whether a law of 2013 that, in effect, shuts down more than three-quarters of the 40-odd abortion clinics in Texas runs foul of a 1992 precedent prohibiting states from unduly imposing on a woman’s right to choose.

Under the law, abortion providers in Texas must have admitting privileges at a nearby hospital and clinics must be expensively fitted out as “ambulatory surgical centres”. Legislators pitch the requirements as a boon to maternal health; detractors decry them as onerous, unwarranted changes that often leave women with nowhere to turn.

Scott Keller, the Texas solicitor-general, insisted that legislators had women’s best interests at heart. But he faced a barrage of resistance from the court’s energised liberal jurists. The first salvo came from Ruth Bader Ginsburg, 83 this month. She jumped on Mr Keller’s suggestion that the new law left 25% of Texas women more than 100 miles from the nearest abortion clinic, “not including El Paso, where the Santa Teresa, New Mexico facility” is just a few minutes’ drive away. Justice Ginsburg noted that New Mexico law does not require surgical standards or admitting privileges. Doesn’t Texas say that “we need these things […] to protect our women”? Mr Keller repeated that women in El Paso often use the facility to obtain abortions.

Justice Stephen Breyer probed the law’s justification. “Go back in time to the period before the new law was passed,” he said. “Where in the record will I find evidence of women who had complications” stemming from their abortions and “could not get to a hospital” under the previous regime but would have made it to a hospital under the new law? Mr Keller looked defeated. He grew meeker still when pressed by the three female justices to explain why Texas fretted so about abortion, one of the safest medical procedures, while failing to insist on surgical facilities for far riskier ones, like colonoscopies.

Despite the fun the liberal justices had with Mr Keller, Texas may not lose Whole Woman’s Health v Hellerstedt when a ruling arrives in June. It would take five justices to overturn the decision upholding the Texas law, and Anthony Kennedy did not seem keen to be the decisive vote. Though he noted that the law served to “increase the number of surgical procedures as opposed to medical procedures, and that this may not be medically wise”, he wondered whether the plaintiffs had presented enough evidence that fewer clinics led to a crisis of abortion supply.

A 4-4 split would let the Texas law stand, and allow other states in the Fifth Circuit to swipe at abortion access in similar ways (as Louisiana is already doing). But it would not bind the rest of the country. As the US solicitor-general, Donald Verrilli, neatly summed it up before the justices, the question boils down to whether the right to abortion “really only exists in theory” or “in fact, going forward”.