In recent years, many states have made it easier to regain the right to vote after a conviction, either through legislation or by executive action. But a handful of states, particularly in the South, continue to be guided by the ghosts of the post-Civil War era, when disenfranchisement laws were aimed at newly freed blacks. The brunt of today’s laws that prohibit felons from voting still falls disproportionately on minorities, who make up more than one-third of those affected. In Florida, Kentucky and Virginia, more than one in five African-Americans cannot vote because of a conviction.

Despite some progress, the United States remains an extreme outlier in allowing lifetime voting bans. Most industrialized nations allow all nonincarcerated people to vote, and many even allow voting in prison.

Adding insult to injury, felon disenfranchisement laws — which are explicitly permitted by the 14th Amendment to the Constitution — are devoid of both logic and supporting evidence. They undermine the citizenship of people who have paid their debt to society, and possibly at a cost to public safety. As Mr. Holder pointed out, a study by a parole commission in Florida found that formerly incarcerated people banned from voting were three times as likely to re-offend as those who were allowed to vote.

Mass disenfranchisement also has serious political consequences. According to a 2002 study, disenfranchisement laws may have determined the outcome of seven Senate races — and thus control of the Senate throughout the 1990s — and a presidential election. While George W. Bush won Florida by 537 votes in 2000, more than 800,000 Floridians with criminal records were barred from voting.

Regardless of which party might benefit most at the polls, repealing felon disenfranchisement laws is in the interest of upholding American ideals. And it has increasing bipartisan support; Senators Rand Paul of Kentucky and Mike Lee of Utah, Republicans who have promoted criminal-justice reform on a larger scale, are also pushing to scale back or end these laws. Even after someone has completed a sentence, Senator Paul said in September, “the punishment and stigma continues for the rest of their life, harming their families and hampering their ability to re-enter society.”