In Florida, Kentucky, Tennessee, and Virginia, more than 20 percent of the voting-age black population will be legally banned from voting this November.

That estimate comes from a new report by the Sentencing Project, which looked at the effect of felony disenfranchisement laws on Americans’ voting rights.

The report estimated that more than 6.1 million Americans, including more than 2.2 million black Americans, will be unable to vote in the 2016 election. That’s about 2.5 percent of the overall voting-age population and 7.4 percent of the black voting-age population.

According to the report, the people currently in prison make up less than a fourth of the disenfranchised. The rest are living in their communities, barred from voting due to past felonies or still serving parole or probation for their crimes — “meaning that about 4.7 million adults who live, work, and pay taxes in their communities are banned from voting,” the Sentencing Project noted.

The report found that the number of disenfranchised voters keeps going up as more and more people are engulfed by the criminal justice system. In 1976, nearly 1.2 million people were disenfranchised. In 1996, more than 3.3 million were. And in 2010, nearly 5.9 million were. To put those numbers in context, the US population has increased by about 50 percent since 1976 — yet the number of disenfranchised Americans has more than quintupled since then.

The effect is unequal by race: As the number of disenfranchised Americans continues climbing, black adults suffer a brunt of the consequences as they’re disproportionately policed, arrested, and incarcerated. “Whereas only 9 states disenfranchised at least 5 percent of their African American adult citizens in 1980,” the report found, “23 states do so today.”

Most states block people with criminal records from voting in some way

Only Maine and Vermont allow everyone to vote regardless of criminal record. Most states don’t let felons who are in prison, on parole, or on probation vote. And 10 states, including Virginia, stopped at least some felons from voting after they completed their sentences, according to the American Civil Liberties Union.

But due to a confluence of socioeconomic factors — such as poverty, unemployment, segregation, and neglect by the police when it comes to serious crimes — black adults are much more likely to go to prison than their white counterparts. A previous review of the research by the Sentencing Project concluded that throughout various time periods in the past few decades, the higher crime rates in black communities only explained about 61 to 80 percent of black overrepresentation in prisons. This means that up to 39 percent of the racially disparate rate of imprisonment is attributable to other factors, including, potentially, racial bias or past criminal records influencing a prison sentence.

Whatever the reason, the result is disenfranchisement laws have a disproportionate impact on the black electorate.

Ex-prisoners face other “collateral consequences” beyond losing their voting rights

Restrictions on voting are an example of the “collateral consequences” that people can face after they complete their sentences. But they’re just one example.

Another one: It’s legal in most states for employers to ask in job applications about someone’s criminal record, and not hire someone for a prior crime — even something as minor as a marijuana possession offense. But this can make it much more difficult for inmates to reintegrate into society: If they can’t get a job, they’re much more likely to turn to criminal activities to make ends meet. So reformers started a campaign to “Ban the Box,” which seeks to stop employers from asking about criminal records in job applications — although they can do criminal background checks later on in the hiring process.

Collateral consequences apply to all sorts of other issues, as well. People who have served out their felony convictions often can’t apply for public housing or Pell Grants to pay for college tuition. They can’t receive welfare benefits. They frequently can’t serve on juries.

Supporters of collateral consequences say ex-criminals are simply suffering the consequences of their actions and shouldn’t be able to use taxpayer resources like welfare, public housing, or Pell Grants. But these restrictions can make it more difficult for an inmate to stay afloat and find a job, and they signal that society will never accept him — making him much more likely to turn back to a life of crime.

In The New Jim Crow, a groundbreaking book about racial disparities in the criminal justice system, Michelle Alexander pointed to these collateral consequences — and how they disproportionately hurt people of color — as an example of a new form of racist social control:

Rather than rely on race, we use our criminal justice system to label people of color “criminals” and then engage in all the practices we supposedly left behind. Today it is perfectly legal to discriminate against criminals in nearly all the ways that it was once legal to discriminate against African Americans. Once you’re labeled a felon, the old forms of discrimination — employment discrimination, housing discrimination, denial of the right to vote, denial of educational opportunity, denial of food stamps and other public benefits, and exclusion from jury service — are suddenly legal.

The disenfranchisement estimates from Florida, Kentucky, Tennessee, and Virginia reflect this disproportionate system — one that strips more than one in five black voting-age citizens in those states of their most basic democratic right.

Watch: The racism of the US criminal justice system in 10 charts