SHREVEPORT, La. — The Supreme Court's next big abortion challenge comes from here in Louisiana. If the state's politicians had their way, so would the one after that. And also the one after that, until Roe v. Wade was no longer the law of the land.

Since the Supreme Court’s 1973 ruling protecting a woman’s constitutional right to abortion, no state has passed more restrictions on the procedure, a national study shows: 89 and counting.

A repopulated and more conservative Supreme Court on Wednesday will consider one of those Louisiana laws, and some politicians here wonder if it might be the breakthrough they’ve been waiting for in a decades-long effort to rid the state, and the nation, of abortion.

“I prayed one day that it would come, but I never thought it would be with this bill,” said state Sen. Katrina Jackson, a Democrat who calls herself “pro-whole life” and says she has been “very aggressive” in pursuing legislation to impose more restrictions.

“In a post-Roe v. Wade society, I always figured Louisiana would be there. With a number of other states maybe, but Louisiana would always be one of them.”

Abortion providers say Jackson’s law would force two of the state’s three abortion clinics to close.

It’s hard to overstate what a decision about this law — requiring difficult-to-obtain hospital admitting privileges for doctors who perform abortions in clinics — will reveal about this Supreme Court and its jurisprudence on what remains one of the nation’s most politically divisive topics.

It will be the first time the two justices selected by President Trump, Neil M. Gorsuch and Brett M. Kavanaugh, confront the merits of an abortion case. It marks a key moment for Chief Justice John G. Roberts Jr., who has never voted against an abortion restriction, in his pivotal role at the court’s center.

And because Louisiana’s law is identical to one from Texas that a different Supreme Court struck down in 2016, it will test the new court’s commitment to respecting past decisions. The Trump administration says the court should uphold the Louisiana law by distinguishing conditions there and in Texas; if not, it should overturn its not-yet four-year-old precedent.

Julie Rikelman of the Center for Reproductive Rights, who will argue June Medical Services v. Russo before the Supreme Court, said there are no meaningful differences.

“Louisiana enacted it knowing that the identical law in Texas had just closed half of the clinics there,” Rikelman said in an interview. “Nothing has changed that would warrant a different outcome. If the law takes effect, it will mean that abortion is almost inaccessible in Louisiana, even though it is supposed to be a constitutional right.”

Rikelman’s client, Hope Medical Group for Women, is housed in a nondescript brick building in a Shreveport neighborhood. Kathaleen Pittman has worked there since 1992. That happens to be the year the Supreme Court reaffirmed Roe, but also made it clear states could regulate and restrict abortion, so long as the law doesn’t impose an “undue burden” on a woman’s right.

“At least twice today, I’m going to answer the phone and somebody’s going to say, ‘I just want to make sure you’re still there. Is abortion still legal in Louisiana?’ ” Pittman said in an interview in her clinic office.

She said she explains to such callers that the law in question is not in effect and that it is now up to the Supreme Court. “I say, ‘For now, abortion is legal in all 50 states.’ That’s, like, becoming our tag­line.”

A bipartisan effort

That abortion is still legal in Louisiana is not for a lack of dedication on the part of its lawmakers.

“Abortion is the American genocide,” said former state senator John Milkovich, whose law office is less than a five-minute drive from the Hope clinic. “My goal as a legislator was to stop abortion: simply shut down the abortion clinics in Louisiana and kick the abortionists out of the state.”

Among the bills he sponsored are those that sought to ban abortions after a woman has been pregnant for 15 weeks, and another after six weeks. Milkovich was irked when the state attorney general said the laws would not go into effect unless similar laws in Mississippi were upheld by the U.S. Court of Appeals for the 5th Circuit, the same court that upheld the law on admitting privileges.

As it turned out, both of Mississippi’s laws were struck down as inconsistent with the Supreme Court’s current abortion jurisprudence.

Many of Louisiana’s laws have met the same fate — “they’re getting tired of paying our legal costs,” said Nancy Northup, president of the Center for Reproductive Rights, whose group has handled many of the challenges.

One thing that is striking about the state’s antiabortion legislation is that it is a bipartisan effort. Milkovich is a Democrat, and so is Jackson. Their legislation is signed and supported by Gov. John Bel Edwards, the only Democratic governor in the Deep South.

Edwards absolutely could not have been elected if he had adopted the abortion rights position of national Democrats, said Milkovich, who was defeated in his reelection bid in a battle with another Democrat and a Republican.

“Faith is part and parcel of our worldview in Louisiana,” Milkovich said. “It’s a driving force in our public life, and that certainly includes the decisions we make about who should be in government positions.”

Jackson describes herself as a “pro-life feminist,” and she has drawn attention nationally as a female African American Democrat who opposes abortion.

“I think what’s unique about Louisiana is our openness about it,” Jackson said in her office across the street from the University of Louisiana at Monroe, about 100 miles from Shreveport. “There are pro-life Democrats all over this nation, but they have a tendency to stay quiet because it’s not popular in the party, nationally.”

Jackson said there are differences between her and Edwards, on one hand, and some Republicans, on the other.

“They are pro-birth . . . but never really advocate that the child that person chooses to have has a chance at the American Dream,” she said. “We believe in life from womb to the tomb, from conception until death, and we fight for it.”

She noted that Edwards’s first act as governor was to expand Medicaid under the Affordable Care Act, something his Republican predecessor had refused to do. Improving schools, providing health insurance, expanding job opportunities are what the state must offer “when we ask the woman not to go to the abortion clinic,” Jackson said.

But she contends the admitting privileges law is not antiabortion. “I thought it was common sense,” she said.

It sounds common sense enough that in a recent poll, about 70 percent of Americans said they supported Roe’s protection of abortion rights, but they also approved of the admitting privileges requirement.

“To the average person, it sounds so benign,” said Pittman, the clinic’s director. But she said there are numerous reasons it is difficult, including that the need for hospitalization after abortion is so infrequent that doctors cannot admit enough patients to meet minimum standards.

Women who require hospitalization are admitted regardless of the doctor’s privileges, and Pittman noted that the Supreme Court in 2016 found that the requirement provided no discernible health benefit to women.

“They talk out of both sides of their mouth,” Pittman said of legislators. “The forced-birthers say it’s for women. . . . But at the very next news conference, they say we’re getting really close to having Louisiana be the first state without an abortion clinic.”

Jackson bristled at the suggestion that the law is a disguised attack on abortion. She is a “very intentional” legislator, she said, meaning that when she sponsors an antiabortion bill, it is clear.

Louisiana already has a trigger law that says if the Supreme Court ever reverses Roe, abortion will be illegal in the state. But Jackson is asking voters this fall for insurance, by approving an amendment that makes clear nothing in the state constitution provides abortion rights to women.

Roberts is the one to watch

In the 2016 case from Texas, Whole Woman’s Health v. Hellerstedt, the Supreme Court said the admitting privileges law had “no health-related benefits” and would result in about half of the state’s abortion clinics closing.

That added up to an undue burden on a woman’s right to abortion, the majority said in a 5-to-3 ruling. (The court was with eight members because Justice Antonin Scalia had died earlier in the year.)

A district judge made similar findings about Louisiana’s law. The doctors who perform abortions tried to comply with the law’s directive to obtain admitting privileges at a hospital within 30 miles of the clinic but could not, he ruled after hearing evidence in a six-day trial.

He agreed that as a result, two of the three clinics would probably close.

The requirement “provides no significant health benefits to women,” the judge said, nor did it serve any credentialing function.

But a panel of the 5th Circuit, which had also upheld the Texas law before the Supreme Court stepped in, disagreed.

It also said that the requirement provided only minimal benefits but that the choice should be the state’s. The law brought abortion providers in line with standards Louisiana has for other ambulatory surgical centers, the judges said, and they disagreed that the doctors had tried hard enough to get admitting privileges.

Those who had privileges could make up for those who did not, the judges said.

Now, a very different Supreme Court will review that decision.

In the Texas case, the court’s four liberals were joined by Justice Anthony M. Kennedy, who also provided the pivotal vote to reaffirm Roe in 1992.

Scalia’s seat has been filled by Gorsuch, and Kavanaugh has replaced Kennedy. In a procedural decision last year, both voted to let Louisiana’s law go into effect while the legal battles continued, which abortion providers say would have left only one clinic in New Orleans in operation.

Trump promised he would nominate justices who opposed abortion rights, and legislators such as Milkovich are hopeful. Trump “has made it a priority. Other presidents have given it lip service,” he said

Roberts, who dissented in the Texas case, joined the court’s liberals in halting the 5th Circuit’s decision until the Supreme Court could consider it. He will be most closely watched in Wednesday’s argument.

In the cases the court has considered since Roberts joined the court in 2005, he has never found that an abortion restriction goes too far. But he also defends the court’s reputation and its commitment to honoring past decisions, unless there is good reason to change.

The court is considering not only the 2016 precedent in the Texas case, but also one from more than 40 years ago that gives abortion providers standing to challenge laws on behalf of women who want abortions, rather than requiring the women to bring suits.

In an unusual friend-of-the-court brief, the American Bar Association noted the consequences.

“Confidence in the integrity of any judicial system, and respect for that system, is enhanced if the citizenry is convinced that judicial decisions are not arbitrary, the product of the prejudices of the decision-maker, rather than the law,” it said in a brief supporting the abortion clinics.

From the other side, more than 200 members of Congress, almost all of them Republicans, told the court it was time to act. The constant legal battles show the “unworkability” of the decision in Roe, they said, and suggest it and the court’s subsequent decisions “should be reconsidered and, if appropriate, overruled.”