Why should we care today about these long-ago decisions? Because in a legal environment that relies so heavily on precedent the shadow of the retreat from Reconstruction still hangs over contemporary jurisprudence. To this day, the 13th Amendment has almost never been invoked as a weapon against the racism that formed so powerful a bulwark of American slavery. The right to vote remains insecure. In 2013, the Supreme Court invalidated the 1965 Voting Rights Act’s requirement that jurisdictions with long histories of discrimination in voting obtain prior federal approval before changing suffrage rules. Many states have interpreted the decision as a green light to enact laws to restrict the voting population in ways that predominantly affect racial minorities and the poor.

Regarding the 14th Amendment, the record is mixed. In many ways, the amendment has undergone an astonishing expansion, made possible by the fact that its language applies to all Americans, not just blacks. The amendment provided the basis for a series of decisions requiring states to act in accordance with the liberties enumerated in the Bill of Rights — a tremendous enhancement of the rights of all Americans. It was employed in the pioneering legal arguments of Pauli Murray and Ruth Bader Ginsburg that persuaded the courts to apply its Equal Protection Clause to discrimination based on gender. It was recently invoked in affirming the right of gay and lesbian couples to marry.

When it comes to the status of black Americans, however, the 14th Amendment’s promise has never been fulfilled. Even at the height of the civil rights movement, the Warren Court, which dismantled the legal edifice of Jim Crow, could not bring itself to admit that for decades the justices had been wrong. Thus, in upholding the Civil Rights Act of 1964, which barred racial discrimination by businesses of all kinds, the court relied on the original Constitution’s Interstate Commerce Clause — as if the act’s purpose had been to facilitate the free flow of goods, not to end demeaning discrimination against American citizens. Basing the ruling on the 14th Amendment would have been more logical, but it would have required the justices boldly to repudiate decades of rulings that the amendment can be enforced only against actions by the states.

As the court has grown more conservative in recent years, it has become more sympathetic to white plaintiffs complaining of reverse discrimination than to blacks seeking assistance in overcoming the legacies of slavery and Jim Crow. Some of the justices today view “racial classifications,” not inequality, as the root of the country’s race problems. They therefore oppose all race-conscious efforts to promote equality in education, employment and other realms. The court today, like the justices in the late 19th century, uses the 14th Amendment to expand the rights of corporations, as in the Citizens United decision that ended limits on political spending. And the state action doctrine survives. For example, a 2000 decision, United States v. Morrison, held that the Constitution authorizes federal action to combat violence against women only if the violence is “state-sponsored.”

Our Constitution is not self-enforcing, and progress is not necessarily linear or permanent. From his threat to exclude the American-born children of undocumented immigrants from the 14th Amendment principle of birthright citizenship to his silence, or worse, in the face of a resurgent white nationalism, President Trump has routinely exhibited behavior suggesting that the pre-Reconstruction definition of citizenship based on whiteness retains its power in parts of society today. But the Reconstruction amendments survive, as does the interpretation of their meaning advanced by Justice Harlan, the Brotherhood of Liberty and others. In a different political environment their latent power may yet be employed to promote the ideal of equal citizenship for all.