A law championed by Senate Democrats (including one named Joe Biden) to undermine a Supreme Court ruling written by Justice Antonin Scalia has become the latest obstacle to the Affordable Care Act.

Who says Washington’s not bipartisan?

Of course, no one knew back in 1993 that the Religious Freedom Restoration Act (RFRA) would one day be invoked by business owners who say their religious beliefs forbid offering employees health insurance plans that cover some types of contraceptives.

When the RFRA was proposed, it had the support of the American Civil Liberties Union and religious lobbyists, rolled through Congress with near-unanimous support, and was happily signed by President Bill Clinton.

Now it is at the center of challenges against the contraceptive requirement. The Supreme Court next month will hear from arts-and-crafts giant Hobby Lobby and a Pennsylvania cabinet-making company named Conestoga Wood; owners of both enterprises say they run their businesses to reflect their deeply held religious beliefs.

The First Amendment holds that “Congress shall make no law respecting an establishment of religion [the establishment clause] nor prohibiting the free exercise thereof [the free-exercise clause].” Against that backdrop, the cases raise important questions of separation of church and state, equal treatment for female workers, and whether corporations, a la Citizens United, have a right of religious expression to which the RFRA applies.

They have created an outpouring of amicus briefs, mostly favoring the companies, with advice for what the court should do. But one stands out from the others because of its blunt assessment about what the justices should do with the RFRA: declare it unconstitutional.

“RFRA is Congress’s overt attempt to takeover this court’s role in interpreting the Constitution,” writes Marci A. Hamilton, a constitutional scholar representing a coalition of nonbelievers and others, such as the Survivors Network of Those Abused by Priests.

The act “accords religious believers extreme religious liberty rights that yield a political and fiscal windfall in violation of the clearest commands of the Establishment Clause.”

The background is a 1990 Supreme Court case. After years of decisions that accommodated religious practices, the court seemed to draw a line in a case involving Native Americans who were fired for illegally smoking peyote during a religious ceremony.

The court said it would be “courting anarchy” to allow individuals to claim a religious exemption from laws that were neutral and generally applied to the rest of the population. Scalia wrote the opinion for five other members of the court.

Congress responded three years later with the RFRA. It says that government may not pass a law that “substantially burdens a person’s exercise of religion,” and it requires courts to apply strict scrutiny: whether there is a “compelling” reason for the law and whether it is narrowly tailored to accomplish the goal.

Hamilton said that the law was all about usurping the Supreme Court’s power. “RFRA is a formula that would make it possible for Congress to meddle with any constitutional doctrine and decision, and move the court to the sidelines as political winds shift constitutional standards by simple majority vote,” she wrote.

The Supreme Court said in 1997 that the RFRA could not be applied to state and local laws, but it has not confronted the question of its constitutionality.

Hamilton, a professor at the Benjamin Cardozo School of Law at Yeshiva University who argued the 1997 case, said she wanted to raise the question because no one else will.

Although some legal scholarship have raised questions about the constitutionality of the act, religious groups obviously have no reason to question it because it affords them greater protection, and the administration has raised no objection.

Hamilton’s brief drew attention as the documents in the case were filed last week — Lyle Denniston of Scotusblog highlighted it. Although the contraceptive challenges will be one of the court’s most charged cases of the term, there is little support elsewhere in the briefs for the view that the RFRA is unconstitutional.

“All three branches agree — RFRA is fine,” said Richard Garnett, a law professor at the University of Notre Dame.

Congress may have criticized and been motivated by the court’s ruling in the peyote case, he said, but that doesn’t mean the law it passed usurped the court’s role. It simply wrote into federal statutory law accommodations for religion, he said.

“In the context of litigation, the Supreme Court’s interpretations control,” Garnett wrote in an e-mail. “But that does not limit the power of Congress to say, ‘Fair enough, but we want to hold ourselves to a higher standard than the Constitution requires.’ ”

Hamilton said that she is not sure how the justices will view her brief. But she said she hopes that in light of questions about the law — retired Justice John Paul Stevens said in the 1997 case that he believed RFTA to be unconstitutional — the court might consider asking a third party to brief the argument, or refer the question back to lower courts.

From the bench

“This case . . . is about donning and doffing, two good old Anglo-Saxon words that are not much used any more. Though we still sing ‘Don we now our gay apparel’ at Christmas, and I suppose a well-bred gentleman still doffs his hat to a lady.”

— Justice Antonin Scalia, announcing the court’s Jan. 27 opinion in Sandifer v. United States Steel Corp., regarding rules about changing clothes before and after a work shift.

For previous High Court columns, go to washingtonpost.com/fedpage.