IN 1965, WHEN he signed the Voting Rights Act, Lyndon B. Johnson called the vote “the most powerful instrument ever devised by man for breaking down injustice and destroying the terrible walls which imprison men because they are different from other men.” In the midst of the civil rights movement, Johnson sounded a call to arms against racial disenfranchisement. Nearly 50 years later, that unfortunately remains a battle.

In an election year when many states have added dubious voter ID requirements sure to affect minority voters disproportionately, another set of impediments to the franchise worsens the problem: laws in 11 states, including Virginia, that disenfranchise felons. Given that African Americans constitute 38.2 percent of the prison population but just 12.6 percent of the general population, a disproportionate share of these disenfranchised people are black.

According to a study released this month by the Sentencing Project, about 7.7 percent of the African American voting-age population is disenfranchised, compared with 1.8 percent of the non-African American population. In Virginia, Kentucky and Florida, felon disenfranchisement affects a staggering one in five African Americans. There’s no excuse for that.

The underlying question is why these states disenfranchise felons who’ve served their sentences, paid their dues and rejoined their communities. According to the Sentencing Project, of the 5.85 million Americans subject to felon disenfranchisement, almost half, or 2.6 million, are out of prison. If a purpose of punishment is to rehabilitate persons to become functioning members of society upon their release, why would you deprive those who succeed of a fundamental right of citizenship?

Although states have made advances in restoring voting rights to felons who’ve completed parole, the franchise should be automatically restored after a sentence is completed, as it is in Maryland. Johnson’s words ring hollow when “the terrible walls which imprison men” continue to reinforce inequality in more ways than one.