Justices Samuel Alito and Clarence Thomas.
CNN  — 

References from conservative justices to a long-dormant chastity law during the Supreme Court’s arguments in a major abortion pill case this week are bringing new attention to the 19th century statute, which prohibits the mailing of drugs used for abortions among other “obscene, lewd, lascivious” or “indecent” materials.

The Comstock Act, as the law is known, is not central to the current Supreme Court case. However, comments from Justices Clarence Thomas and Samuel Alito showcase how the law is shaping up to be both a flashpoint in the legal battle over abortion and a potential election-year issue for voters.

There are now calls from within the anti-abortion movement for the Comstock Act to be enforced by the next Republican administration to ban the mailing of abortion medication – a move that would not require any action by Congress nor any blessing from the Supreme Court.

But there is uncertainty and disagreement among anti-abortion advocates about what that means. Some prominent figures in the anti-abortion movement dismiss the possibility that it would be used to effectively ban medication abortion, which depends on the shipment of abortion drugs to providers, even as other abortion foes have said the law – interpreted to its fullest extent – could potentially end not only medication abortion, but abortion altogether.

Abortion rights supporters argue that their opponents are over reading the law and are ringing alarm bells, as at least some justices on the Supreme Court appear to be entertaining a maximalist interpretation of the law’s reach.

Alito wrote the court’s opinion overturning Roe v. Wade, while Thomas is seen as a judicial pioneer in his success in bringing into the legal mainstream views previously seen as fringe. Their interest in the law’s relevance to Tuesday’s case speaks to how the Comstock Act has taken a more prominent role in the efforts to further limit abortion.

“Overturning a constitutional right to privacy that extends to abortion – as reflected in Roe v. Wade – is not their stopping point … they will do anything, even if that is seeking to resuscitate a 19th century statute that was passed before women had the right to vote,” said Skye Perryman, the president and CEO Democracy Forward Foundation.

Comstock and the current case against the FDA

The Comstock Act was first enacted by Congress in 1873 to ban the use of the mail to transport a wide range of “lewd” materials, including pornography, birth control, and drugs or other instruments used for abortion. There were some prosecutions under the law in the initial decades after it was passed, but courts in the early 19th century whittled down its scope, and enforcement of it stopped altogether while Roe v. Wade – the 1973 abortion rights precedent that the Supreme Court overturned in 2022 – was on the books.

The Comstock Act has so far played only a cameo role in the case heard by the Supreme Court on Tuesday, which concerned the federal government’s regulatory approach to mifepristone, one of the two drugs used in medication abortion. The justices are considering a challenge to the changes the US Food and Drug Administration made to mifepristone’s rules that made it easier to obtain – including the FDA’s 2021 move that allowed the drug to be sent to patients in the mail without an in-person doctor’s visit.

(The challengers also argued that mifepristone should be pulled from the market altogether; while a trial judge agreed with them, an appeals court reversed that aspect of the judge’s ruling.)

Among other arguments, the case’s plaintiffs, anti-abortion doctors and medical associations, have invoked the Comstock Act to argue the FDA acted unlawfully by not considering the 19th century criminal prohibition on mailing abortion drugs.

Alito pressed US Solicitor General Elizabeth Prelogar, who was defending the FDA, on those arguments on Tuesday. Referencing the law by its US code number (18 U.S.C. 1461) rather than by its colloquial name, Alito said Comstock was a “prominent provision” and not an “obscure section of a complicated obscure law.”

The Biden administration contends the Comstock Act is not relevant to the current dispute over the drug’s medical regulations, because it is not the FDA’s job to interpret and enforce a criminal statute.

“It’s very clear that the only thing FDA can take into account for restrictions are safety and efficacy concerns in deciding whether to maintain a REMS program,” Prelogar said Tuesday, referring to the types of restrictions that are currently on mifepristone’s use.

Thomas also invoked the statute, asking a lawyer for the mifepristone manufacturer how she would respond to the argument that “mailing your product and advertising it would violate the Comstock Act.”

Other justices on the court did not show interest in digging into the Comstock Act’s significance or many of the other legal questions the case presents. Instead, there appeared to be a majority willing to toss the case because the challengers have failed to show standing, i.e. the type of harm that would warrant judicial action.

But much attention will be paid to any commentary about the statute, even if just in a dissent, when the Supreme Court issues its ruling in the case in the coming months.

“We could well see Comstock referenced in the court’s ultimate decision, either with respect to the outcome of this case, or a broader signaling of how some of the justices believe this Comstock Act could be used to strip away our right to abortion nationwide altogether,” said Julia Kaye, a senior staff attorney with the ACLU reproductive freedom project, on a press call after the arguments.

Comstock’s enforcement in the future

With the Supreme Court unlikely to reach any conclusions about the law’s reach in the case it heard Tuesday, the candidate who wins the presidency in 2024 could decide whether the Comstock Act will take on new life.

The Justice Department under President Joe Biden has issued internal legal guidance asserting that the Comstock Act’s prohibitions do not apply to drugs used for lawful abortions. The DOJ’s Office of Legal Counsel opinion – which is binding across the federal government but is not controlling in court – points to court rulings from the early 20th century.

But some legal experts believe that if the DOJ position was reversed under a Republican administration – and the law was interpreted to apply to drugs used in both lawful and unlawful abortions – it could be enforced in a way that would hamstring and potentially end the provision of medication abortion nationwide, because drug manufacturers and distributors would not be permitted to ship abortion pills through the supply chain.

Access to clinical abortion could also be effectively ended, some believe, under an extreme reading of the law, if the Comstock Act was used to prohibit the shipment of tools and instruments used for abortions to abortion providers.

A policy agenda assembled by the Heritage Foundation, an influential conservative think tank, has called for the law to be enforced, but is sparse on the details as to what ends.

Roger Severino, the Heritage Foundation’s vice president of domestic policy, rejected the idea that a future administration would use the law in a way that would make abortion, or even medication abortion, unavailable in states where it is legal.

“The Comstock Act’s implications have been overblown by the pro-abortion side,” said Severino, who previously served in the Trump administration as a top official at the Department of Health and Human Services.

Severino described to CNN a scenario in which misoprostol – the other drug used for medication abortion – would still be accessible to women seeking abortion in states where abortion is legal, since misoprostol also has non-abortion uses.

Some in the anti-abortion movement, including advocates who asked for anonymity to speak candidly to CNN, are wary of a political backlash if the Comstock Act is enforced too aggressively – a backlash that would put pressure on Congress to repeal it altogether – and caution that former President Donald Trump, if he is reelected, should consider the political risks in deciding how his administration should wield the law.

The Trump campaign has avoided publicly weighing in on the Comstock Act or even the related question of how abortion pills would be regulated if he returned to the White House.

People close to Trump told CNN they acknowledge the complexity of the issue, as well as that many leading anti-abortion groups have different opinions on how to approach the legal fight.

The political ramifications of the Supreme Court’s ultimate decision in the current FDA case is also at the forefront of how they approach the subject. As of now, Trump has been “in listening mode,” one of the sources said, and is being advised by several of his top anti-abortion allies on the different angles of the case.

CNN’s Michelle Shen and Alayna Treene contributed to this report.