In a consequential lawsuit seeking to upend the Food and Drug Administration’s approval of abortion pills, Democratic and Republican attorneys general took sides in court filings on Friday.

The suit was filed in November by an anti-abortion group called Alliance for Hippocratic Medicine. They allege that the process the FDA used decades ago to evaluate and approve the drugs used for medication abortions — mifepristone and misoprostol — was unlawful and should be revoked.

The plaintiffs sought an injunction requesting that the FDA’s approval of mifepristone be reversed while the case plays out.

This week, the maker of mifepristone, Danco Laboratories, legally intervened in the case, joining the defense.

The District Court judge overseeing the trial, Matthew J. Kacsmaryk in the Northern District of Texas, was appointed by President Trump. His decision is expected to come sometime after Feb. 24. If he rules in favor of the Alliance for Hippocratic Medicine, access to medication abortion could be thrown into question.

Medication abortion accounts for more than half of all abortions nationwide, according to the Guttmacher Institute, a research group that supports abortion rights. 

There is little legal precedent for a court to overturn an FDA drug approval. But should that occur, the Biden administration would likely appeal such a decision to the 5th Circuit Court in New Orleans, which is generally conservative. The case could eventually wind up at the Supreme Court.

On Friday, New York Attorney General Letitia James led a coalition of 22 attorneys general in filing a brief that argued that if the FDA were ordered to rescind its approval of mifepristone, that would have “devastating consequences” for women across the U.S., regardless of their state’s abortion policy.

Mississippi Attorney General Lynn Fitch, meanwhile, led a group of 22 Republican attorneys general who filed a brief calling the FDA’s approval of abortion pills “deeply flawed.”

Representing the plaintiffs are attorneys from the conservative Christian legal advocacy group Alliance Defending Freedom, which also played a significant role in the Dobbs v. Jackson Women’s Health Organization case that led to the overturning of Roe v. Wade.

Mifepristone has been FDA-approved since 2000 for use in combination with misoprostol to terminate pregnancies up to 10 weeks. Misoprostol, meanwhile, was first approved in 1988 for a different purpose: the prevention of gastric ulcers.

Used together in consult with a doctor, the two-medication regimen successfully terminates a pregnancy around 99.6% of the time, and has a 0.4% risk of major complications, according to the National Library of Medicine.

In court filings last month, the FDA said its approval of mifepristone came after extensive review of the scientific evidence. The agency called the lawsuit “extraordinary and unprecedented,” adding that the plaintiffs have asked the court to upend “longstanding scientific determination based on speculative allegations of harm offered in support of claims and arguments that are untimely, unexhausted, and without merit.”

In its supporting brief on Friday, the Democratic attorneys general argued that reversing mifepristone’s approval would restrict abortion access nationwide and force patients to undergo surgical abortions — which are more invasive and often more expensive — or forgo an abortion entirely. The group also argued it would undermine “the integrity of the FDA-approval process.”

“Blocking access to this safe and effective medication is a dangerous attack on reproductive freedom and public health,” James said in a statement. “Decades of medical and clinical research have proven that medication abortion is safe. Despite these facts and its widespread use, we know this is not a debate about science.”

The Republican attorneys general, meanwhile, argued that the FDA “has acted to establish a nationwide regime of on-demand abortion by licensing sweeping access to chemical abortion drugs — in defiance of federal and state laws.” 

Fitch added in a statement: “In the Dobbs case, the Supreme Court affirmed that states may enact laws that protect unborn life, women’s health, and the integrity of the medical profession, and we will not allow the Biden administration to trample on this fundamental Constitutional building block.”

In the wake of the Dobbs decision, the FDA has taken several measures to protect and expand access to abortion medications. Last month, the agency finalized a rule change that allows retail pharmacies to dispense mifepristone. CVS and Walgreens have both said they plan to dispense the pill in states where abortion is legal.