By Brian M. Rosenthal

The four liberal members of the U.S. Supreme Court took turns tearing into Texas' controversial anti-abortion law at a highly anticipated hearing Wednesday, raising the possibility of a landmark court ruling that could make the procedure easier to access nationwide for years to come.

Justices Ruth Bader Ginsburg, Stephen Breyer, Sonia Sotomayor and Elena Kagan all pressed Texas Solicitor General Scott Keller to explain why the set of abortion regulations that have helped force dozens of clinic closures in the state was medically necessary, repeatedly raising evidence of other procedures that are more dangerous and less regulated.

"There are so many other medical treatments whose complication rates are so disproportionately higher, and the Legislature is only targeting abortion," Sotomayor said at one point, adding that, "The slightest benefit is enough to burden the lives of a million women. That's your point?"

Later, Breyer demanded a single example of a woman experiencing an abortion-related complication and not being able to get care because the previous law was insufficient.

"That is not in the record," the Texas state lawyer was forced to concede.

The abortion providers who brought the case against the Texas law known as House Bill 2 fared better during the 90-minute oral arguments, although they faced questions from Chief Justice John Roberts and fellow conservative Samuel Alito about the evidence that recent clinic closures were actually caused by the regulations.

Justice Anthony Kennedy, a moderate and key swing vote on the court, raised another possible outcome by wondering aloud multiple times whether it might be best to send the case back to Texas for more evidence.

Such a move could allow the case to come back after a replacement has been chosen for former Justice Antonin Scalia, whose death at a West Texas ranch last month deprived the court of its most prominent conservative and tilted the court more in favor of abortion.

A delay also would prolong a nationally watched battle that has been going on since Texas lawmakers first began discussing an ambitious set of abortion restrictions in the fall of 2012.

House Bill 2, approved over a filibuster by then-Democratic state Sen. Wendy Davis, banned abortions after 20 weeks of pregnancy, heavily limited the use of the pill to accomplish the procedure, required abortion doctors to obtain admitting privileges at nearby hospitals and mandated abortion facilities comply with the standards of hospital-style surgical centers.

The latter two regulations are the ones at issue in the case, with opponents arguing that they are medically unjustified and so hard to meet that they have forced widespread clinic closures.

Already, about half of the 41 abortion clinics in operation in Texas before the passage of House Bill 2 have closed. If the law were to be allowed to fully take effect, another 10 that do not currently comply with the law also could shutter.

That could leave nine clinics in a state of 27 million people, and none of those would be south or west of San Antonio.

Supporters say the regulations are common-sense measures that protect women's health and that the closures have occurred for reasons other than House Bill 2.

The case is seen as the most significant abortion-related dispute to come before the Supreme Court since the justices ruled in 1992 that governments could not place an "undue burden" on women seeking the procedure.

The stakes stretch far beyond Texas: Similar laws have been passed in a dozen other states, and, overall, 162 abortion clinics in the U.S. have closed since 2011, according to Bloomberg News.

Both abortion-rights supporters and anti-abortion activists have expressed confidence about the case, although the former group has had more reason for optimism since Scalia's death.

Wednesday's oral arguments were among the first conducted without Scalia.

The swing vote, Kennedy, who could side with the liberals in a 5-3 ruling against the law or side with the conservatives in forcing a 4-4 tie that would leave the law in place but not set a national precedent, did not offer many clues about his feelings during the arguments.

At one point, however, he noted that he had seen evidence that House Bill 2 had increased the percentage of abortions that are conducted by surgery, which is more dangerous -- a statement that was seen by some as encouraging for the abortion providers.

On the other hand, Kennedy appeared at another point skeptical about whether the challenge was even valid given that another lawsuit against House Bill 2 had failed.

Alito also expressed support for that argument and others made by the state. The justice repeatedly asked Stephanie Toti, the lawyer for the providers, for proof about whether the clinics had closed because of House Bill 2 and why the other abortion facilities in the state could not pick up the slack.

"There is very little specific evidence in the record in this case with respect to why any particular clinic closed," Alito said at one point.

Toti responded by saying that 11 of the abortion clinics that have closed shuttered on the day that the admitting privileges went into effect.

Kagan then jumped in to note that another dozen clinics closed when the law was briefly allowed to take effect before a Supreme Court stay.

"It's almost like a perfect controlled experiment as to the effect of the law, isn't it?" Kagan said.

U.S. Solicitor General Donald Verrilli, representing the federal government, also argued against the law during the arguments, which lasted 30 minutes longer than scheduled.

As the hearing went on, activists on both sides of the abortion issue held dueling rallies on the steps of the Supreme Court building.

Abortion-rights supporters, who significantly outnumbered the other side, carried signs such as "Keep abortion legal," "Abortion laws don't eliminate abortion. They eliminate safe abortion" and "HB2 is bad for women (and really, really unconstitutional)."

Several members of Congress spoke at the rally, including U.S. Rep. Barbara Lee, D-California, who said the activists would "keep fighting until women's rights are protected."

The anti-abortion group's signs included "Life counts: All life," "Every child is a wanted child" and "We are a pro-life generation." Among the speakers was U.S. House Speaker Paul Ryan, a Wisconsin Republican.

The two sides mostly avoided each other, but at one point, an anti-abortion activist asked for a moment of silence "for all killed by abortionists," and the other side responded by yelling. Many yelled "repro rights," for reproductive rights.

Laura Hecht-Felella, 25, of New York, a staffer with National Advocates for Pregnant Woman, said it was "really exciting and just inspiring to be here with so many people who care about these issues so much."

Across the square, anti-abortion activist Jonathan Darnel worried about what would happen in the case.

Darnel, 34, of Virginia, said he felt that Scalia's death had made the court "lopsided" in favor of abortion. Still, he said he was remaining hopeful.

"Ultimately, we don't know how it's going to go," he said. "It's anybody's game."

A ruling is expected by June.

(c)2016 the Houston Chronicle