Several hundred members of Congress filed "amicus," or supporting, briefs in a closely watched upcoming Supreme Court case that could decide the future of abortion access.

The brief from 207 mostly GOPers included signatures from Sens. Mitt Romney, John Cornyn, Marco Rubio and Reps Steve Scalise and Liz Cheney. The opposing brief was signed by 197 members of Congress -- a mostly Democratic group that included Sens. Chuck Schumer and Dianne Feinstein, as well as Reps. Nancy Pelosi and Jerry Nadler.

The mostly Republican signatories -- 39 senators and 168 representatives -- argued that Louisiana clinics are rife with safety violations -- and that the time is ripe to reconsider the legal underpinnings of Roe v. Wade, the seminal 1973 Supreme Court case that established a constitutional right to an abortion. All were Republicans except Democratic Reps. Dan Lipinski and Collin Peterson.

"Roe's jurisprudence has been characterized by Delphic confusion and protean change," the members wrote.

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They argued that Roe claimed to establish a fundamental right to abortion -- only for the 1992 Supreme Court case Planned Parenthood v. Casey to establish a new standard, which required that the government not impose an "undue burden" on abortion rights. Multiple incoherent exceptions and balancing tests have since been employed by the courts, according to the amicus brief.

For example, one Supreme Court case post-Casey defined a law as an "undue burden" on abortion rights if in a "large fraction of the cases in which [the law] is relevant, it will operate as a substantial obstacle" -- a test later abandoned. then revived by the high court.

Meanwhile, the Democrats primarily argued that stare decisis, the principle through which existing Supreme Court cases are given deference, dictated that Roe should remain good law.

The high court will hear arguments in March on the case, which involves a Louisiana law that requires doctors who perform abortions to have admitting privileges at a nearby hospital. The Louisiana statute is virtually identical to a Texas law that the Supreme Court struck down in 2016.

That decision came when Justice Anthony Kennedy was on the bench and before President Donald Trump’s two high court picks, Justices Neil Gorsuch and Brett Kavanaugh, joined the court.

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At least one justice is likely to find the amicus brief agreeable. Last summer, in a concurring opinion in a Supreme Court case, Justice Clarence Thomas issued a lengthy call for his colleagues to overturn "demonstrably erroneous decisions" even if they have been upheld for decades -- prompting legal observers to say Thomas was laying the groundwork to overturn Roe.

The 5th Circuit Court of appeals recently lifted an injunction issued by a lower court against the Louisiana law, but the Supreme Court quickly restored the injunction.

The Supreme Court's upcoming decision comes as abortion has taken center stage in legal battles across the United States, with numerous states passing stricter limits on abortion.

Last August, Planned Parenthood announced that it was pulling out of the Title X federal family planning program rather than abide by a new Trump administration rule prohibiting participants from referring patients for abortions.

Fox News' Bill Mears, Shannon Bream and The Associated Press contributed to this report.