New Jersey Democrats are acting as if it’s the 1930s and their party is again enforcing its Jim Crow laws. Despite the state never having outlawed interracial marriage, the assembly is moving to protect it against a nonexistent threat from conservatives on the Supreme Court.

This effort is built on the left’s shock at the overturning of Roe v. Wade, which didn’t ban the practice of abortion but returned it to the states to decide. Now, Democrats and aligned special interest groups have seized on the court’s decision to fund-raise and demagogue, casting the 1967 Supreme Court case banning discrimination against interracial couples, Loving v. Virginia, as in mortal peril.

The American Civil Liberties Union claims — below a full-screen ad asking for donations — that “the legal reasoning that Justice Alito used to overturn Roe could be applied to undo Loving v. Virginia, signaling a new threat to interracial marriage as we know it.”

The only signaling, of course, is the virtue signaling, repeating the stunt of President Biden signing the Respect for Marriage Act to defeat this same imaginary enemy in December. It’s as if America didn’t long ago bury the slur of “miscegenation” — like President Lincoln, a Republican — under 4,000 pounds of righteous metaphorical concrete.

A September 2021 Gallup poll found a record 94 percent support intermarriage, with the percentage of white and non-white adults identical, accounting for the margin of error. Mr. Biden makes a fetish of pointing out mixed-race couples in commercials, almost as if it’s atonement for his opposition to integration through busing students, using the dog whistle that it would turn schools into “a racial jungle.”

“If people here think that this legislation was intended to be thought-provoking,” the sponsor of the intermarriage bill in New Jersey’s Assembly, John McKeon, said, “you’re right.”

Yet if citizens are pondering any danger, count me as one New Jersey resident who reckons it’s the state’s manifest problems of high taxes, crumbling roads, failing schools, and corruption under Democratic control in Trenton.

Mr. McKeon’s bill is an attempt by the state’s Democrats to cast themselves as standing with the 94 percent against the tiny fringe of all races who say — in the words of those segregationists that Mr. Biden often speaks of with such fondness — “Stick to your own kind.”

It’s unfortunate to have to mention that three of the nine members of the Supreme Court — Justices Clarence Thomas, Sonia Sotomayor, and Ketanji Brown Jackson — married partners of other racial backgrounds, while Chief Justice Roberts adopted two Hispanic children and Justice Amy Coney Barrett two from Haiti. Yet New Jersey Democrats pushing this pointless legislation ignore our blended court, as it would dim the virtue signal.

“However unlikely that the right to an interracial marriage would be threatened in this state,” the chairman of the Assembly’s Judiciary Committee, Raj Mukherji, said, as if it’s not already protected by federal law, “if you agree that such a prohibition would be immoral, what’s the harm in codifying that into state law?”

The harm is digging up the ghosts of yesterday’s Democratic Party, fanning a false fear, and blaming it on the Republicans of today. It’s not just that its divisiveness dashes hopes that Mr. Biden meant it when he promised to unify the country. This bill tells multiracial children — a demographic increasing faster than any other, according to the Census — that their families may be torn asunder at any moment.

Tormenting those kids seems not to trouble the sleep of those Democrats backing the legislation. They’ve introduced the bill and they’ll get the credit, since no Republican will dare vote against the farce, enabling Messrs. Mukherji and McKeon and others to fundraise on having “saved” something that faced no real danger in the first place.

There’s less evidence of a monster out to tear apart multiracial couples and families than there is of Bigfoot’s existence or of the mythical Jersey Devil in the Pine Barrens, but perhaps if Trenton Democrats could convince citizens of their state that those creatures are Republicans, they’d propose a law banning them, too.