The U.S. Supreme Court heard oral arguments Wednesday for Whole Woman’s Health v. Hellerstedt, a case challenging a Texas law that requires doctors who provide abortions to hold admitting privileges at local hospitals and for clinics meet the same standards as ambulatory surgical centers.

The law has already forced more than half of the clinics in Texas to shutter their doors, and if it upheld, 10 of the remaining 19 also would be forced to close. And some experts worry that it could have an even greater effect. While other laws, including a measure requiring women to see a sonogram of the fetus and a 20-week abortion ban, have passed in the state, the Texas law being challenged Wednesday is viewed by many as one of the central abortion debates of the modern era.

“We just didn’t see laws as restrictive as the ones we’ve seen in the past five years,” David Brown, a staff attorney for the Center for Reproductive Rights and one of the attorneys bringing the case against Texas, said. “We didn’t have to bring the kinds of lawsuits we've been bringing over and over again over women’s constitutional rights.”

Texas has been the center of the abortion debate since Roe v. Wade, the 1973 case that determined women have a constitutional right to abortion. Since then, anti-abortion laws have been crafted in states across the U.S., but these types of laws are often seen first in Texas, such as a 2011 law that requires women to watch a sonogram of their fetus 24 hours before a scheduled abortion.

Sonogram laws have since passed in Louisiana and Wisconsin, as Texas passing anti-abortion legislation often builds momentum for similar laws in other states, said Nan Little Kirkpatrick, executive director of the Texas Equal Access Fund, a group formed in 2005 to provide grants to low-income Texans to get abortions.

“Texas has been a testing ground,” Kirkpatrick said. “If you wanted to see if a piece of anti-choice legislation can get passed, Texas is a good place to start."

Texas wasn't the first state to pass laws limiting how long into a pregnancy a woman may have an abortion, but in 2013, the state passed a law that said no abortions can take place after 20 weeks of pregnancy, Vicki Saporta, president and CEO of the National Abortion Federation, a Washington, D.C.-based organization of abortion providers, said.

“Since 2010, you’ve had hundreds of abortion restrictions passed throughout the country,” Saporta said.

The 2013 law being looked at Wednesday, known as HB-2, requires that abortion doctors have admitting privileges for their patients to hospitals within 30 miles of a clinic and that a clinic meet the standards for an ambulatory surgical center, so a patient can get surgery if they are in critical need. While Kirkpatrick said the TEA Fund has always gotten a lot of calls for financial assistance for abortions, they have seen more calls coming in since HB-2 was passed.

It’s unclear how the court will rule, but the death of the late Justice Antonin Scalia may complicate matters. A four-four split would mean the appellate court ruling, which upheld the Texas law, would stand, but it wouldn’t create a national precedent.

Most court watchers will be looking at how Justice Anthony Kennedy will vote — voting with the court’s four liberals would tip the balance to create a national precedent striking down laws like HB-2. Kennedy voted with the plurality in the 1992 case Planned Parenthood v. Casey, which upheld Roe v. Wade's right to access abortion but allowed states to restrict access as long as it does not create an “undue burden.”

Since the Texas law was passed, the admitting privilege requirement alone has caused about half the state’s clinics to close, leaving only 19 open across the large state. The laws have placed the greatest burden on low-income women, who often have to drive miles across rural Texas to clinics. And because of the 24-hour wait time, these women either have to pay to make the trip twice or to stay in a hotel, Kirkpatrick said.

Many of the Texas clinics closed simply because they knew they weren’t going to get admitting privileges to a hospital, which aren’t required to present abortion clinics with admitting privilege applications, Kirkpatrick said. A lack of hope, however, is not the only reason clinics had to shutter.

“The other thing is in order to get admitting privileges, you have a requirement that you have to have so many admitting patients,” Kirkpatrick said. “If you're never going to be admitting patients to the hospital, you struggle with keeping the admitting privileges because you’re not using the hospital at all."

Saporta said there is no reason for an abortion to be done in an ambulatory surgical center, as a woman who has complications during an abortion can be taken to an emergency room. This part of the law has been stayed until the court decides on the case, but if the law is upheld, there is the possibility that the number of abortion centers in Texas could reduce to nine or 10, as cost of becoming an ambulatory surgical center could be between $1 million and $1.5 million, she said.

“Abortion has one of highest safety records,” Saporta said. “There is no evidence that either one of those provisions lead to greater safety or higher quality care.”