Much of the modern history of civil rights law finds its origin in a famous footnote in a 1938 Supreme Court decision dealing with shipping “adulterated” milk across state lines. But there is another part to that ruling, and a new appeal is asking the Court to bring that part up to date, for use in judging laws that put limits on the way businesses can operate.

If the Court agrees to take on the case of Heffner v. Murphy, it could be opening the possibility that many laws could be struck down simply because the facts behind them are out of date. That could force state legislatures and Congress to reenact the laws, based on today’s actual circumstances, to keep them in force.

The new case involves a dispute over how to apply the “rational basis” test — the least-demanding test that a law must pass to be upheld against a constitutional challenge. In many of the Court’s decisions on regulation of business and commerce, the use of that test rarely leads to nullification of a law. If there is any plausible reason for the law, even if the lawmakers had not thought of it, the Court has indicated, that is sufficient.

The Court used that standard in 1938 in the case of United States v. Carolene Products, upholding the constitutionality of a 1923 law that made it a crime to ship across state borders any milk product that had been blended with non-milk fats or oils. The case involved a product that laced milk with coconut oil; it was sold under the brand name “Milnut.”

What is most famous about that ruling, though, is what has been called the most important footnote in Supreme Court history: footnote 4. After discussing how easy it was to satisfy the “rational basis” test, the Court said in that footnote that it might demand more justification if a law discriminated against “discrete and insular minorities” who lacked political power to protect themselves.

Ultimately, that footnote grew into a broad mandate for imposing tougher standards on laws that discriminate — based on, say, race or — later — gender or sex.

Carolene Products has been cited many times in modern court rulings, and that was because of footnote 4, rather than another part of the opinion in that case. In that other part, the Court said that “the constitutionality of a statute predicated upon the existence of a particular state of facts may be challenged by showing to the court that those facts have ceased to exist.”

A group of about two dozen funeral directors or businesses operating funeral homes and cemeteries in Pennsylvania is seeking to use that standard to bolster their challenge to a set of restrictions imposed on the funeral industry in that state sixty-two years ag9 — in 1952.

Their challenge succeeded in a federal district court, which struck four restrictions, finding them outmoded or antiquated, because of changes in the way funeral homes now operate. However, that result was overturned by the U.S. Court of Appeals for the Third Circuit, which upheld each of the provisions using the “rational basis” test.

The restrictions at issue limit funeral directors to owning only one funeral home plus a branch, limit the directors to carrying on their craft only at those two facilities, require a preparation room for corpses in every facility, and prohibit the serving of food — but not beverages — during funeral services.

The funeral directors and other challengers contended that, whatever the need for each of those restrictions might have been in 1952, they are all outdated now, given how funeral homes actually conduct their business. For example, they argue that, because bodies can be prepared more efficiently at a central location, many of the mandatory preparation rooms in separate facilities go unused, at considerable expense.

The new petition urged the Court to reinforce what the Carolene Products opinion had said about out-of-date facts as a factor in judging a law’s constitutionality. They contend that what the Supreme Court said at that time is, or at least should be, a binding rule of analysis.

The challengers asserted that some lower courts now no longer treat that statement as a binding requirement, while others still follow it. That has set up a conflict, the petition argued, that the Justices should straighten out.

In a point that the new petition stressed several times, it noted that last year the Supreme Court struck down a key part of the federal Voting Rights Act because the facts of racial bias in voting had changed markedly since that Act was passed in 1965. Current burdens imposed by a law, the Court said there, must be justified by “current needs.”

If the Court has in fact abandoned what it said in that part of Carolene Products, the petition argued, the Court should say so, but it should recognize that doing so conflicts with many other areas of constitutional interpretation where the Court does, in fact, judge laws based on today’s factual circumstances.

Pennsylvania has urged the Court to deny review, arguing that the challengers did not raise their rational basis argument in the lower courts, that there is no real conflict in lower courts on the issue, that the statement made in Carolene Products was not a rule but simply a passing comment unnecessary to the ruling, and that even the Supreme Court does not apply the changed-facts approach in applying rational basis review.

The funeral directors’ petition (including the lower court rulings) is here, the state’s brief in opposition is here, and the funeral directors’ reply brief is here.

The case, according to the Court’s electronic docket, is scheduled to be considered by the Justices at their next private Conference, on September 29.

In association with Bloomberg Law