For a century and a half, Floridians have been bound by a policy rooted in the Jim Crow era that restricts who gets to vote. On Tuesday, the state will take a big step away from it and officially implement what advocates say is one of the most significant expansions of the right to vote in modern times.

In November, Florida voters approved a constitutional amendment to do away with the state’s longtime policy of permanently disenfranchising people with felony convictions. The amendment officially takes effect Tuesday. It automatically restores voting rights to people with felony convictions once they complete their sentences entirely, including probation and parole (those convicted of murder and sexual offenses are exempt). The measure ― often referred to as Amendment 4 ― could affect up to 1.4 million people in the state.

“Amendment 4 is the single most significant reform in felony disenfranchisement in American history,” Marc Mauer, the executive director of the Sentencing Project, a criminal justice nonprofit that has studied felon disenfranchisement across the country, wrote in an email.

“Nearly 1/4 of the entire disenfranchised population in the US has been affected by this measure,” Mauer wrote. “The United States is still far out of line compared to comparable nations in this regard, but this measure is nonetheless a major step toward a robust democracy.”

Since 1868, Florida’s constitution has banned anyone convicted of a felony from voting. Until Tuesday, people who wanted to vote again had to ask the governor, who had the ultimate power of deciding who got their rights restored. It was one of the ways Florida lawmakers kept African-Americans from the polls once they legally gained the right to vote.

Until Tuesday, Florida was one of just four states where people with felony convictions are permanently barred from voting unless the governor decides to restore their right to cast a ballot. More than 1 in 5 African-Americans couldn’t vote in the state because of the policy, according to a 2016 estimate by the Sentencing Project.

ASSOCIATED PRESS Florida Gov. Rick Scott (R), who was elected to the U.S. Senate in November, had wide discretion in choosing whether to restore voting rights to people with felony convictions.

Before Tuesday, Florida’s governors had enormous discretion in how they restored voting rights to people. Former governors Jeb Bush and Charlie Crist, for example, implemented rules while in office to streamline restoration. But when Rick Scott took office in 2011, he imposed new rules that required people with felony offenses to wait 5 to 7 years ― depending on their offense ― before they could begin to apply to have their rights restored.

Scott and a panel of Cabinet officials who heard the requests only met four times a year in Tallahassee, and as of last September, there was a backlog of 10,000 people waiting to get a hearing (some people could have their voting rights restored without a hearing). At the hearing, Scott could choose to restore or deny voting rights to anyone and was not required to give an explanation for his decisions.

The number of people who had their rights restored dropped significantly under Scott, and the long wait period, combined with the delay from the backlog, meant that Floridians were still being punished for crimes they committed decades ago.

“It’s hard to overstate the significance of Amendment 4 ― in Florida and in the national and international movement toward universal suffrage as well,” said Christopher Uggen, a professor at the University of Minnesota and co-author of Locked Out: Felon Disenfranchisement and American Democracy.

“The referendum reflects a longstanding tension in the United States between the public’s strong appetite for ‘law and order’ and its deeply held desire to extend civil rights and liberties to all citizens. The voters spoke clearly on this issue, opting for civil rights over the ‘civil death’ of permanent disenfranchisement,” Uggen said.

It’s hard to overstate the significance of Amendment 4 ― in Florida and in the national and international movement toward universal suffrage. Christopher Uggen, University of Minnesota

The effort to change the law was led by Desmond Meade, who couldn’t vote in Florida until Tuesday because of a felony conviction, and the Florida Rights Restoration Coalition. The group is encouraging former felons who believe they can now legally vote to register on Tuesday to raise awareness about the change in policy.

Crist, who is now a Florida congressman, said Monday he would accompany former felons to the polls in St. Petersburg as they register for the first time.

While up to 1.4 million people could be affected by the new measure, there are likely to be more challenges in implementing it. The amendment says voting rights are restored “upon completion of all terms of sentence including parole or probation,” but it’s not immediately clear what “all terms” of a criminal sentence are. Former felons could be required to repay all fines and fees associated with their sentence, for example, which can total hundreds, if not thousands, of dollars.

Local election officials say they haven’t gotten any guidance from state election officials, but many say they will register any voter who swears on their voter registration form that they are eligible to vote. Lying on a Florida voter registration form is a criminal offense punishable by up to 5 years in prison and a $5,000 fine.

There is already a bubbling dispute over how much of a say, if any, lawmakers should get in deciding how the constitutional amendment gets implemented. Activists who supported the amendment say it is “self-executing” and that neither lawmakers nor state officials get a say in how to implement it.

Incoming Florida Gov. Ron DeSantis (R) told The Palm Beach Post in December that the measure should be delayed until the state legislature, which doesn’t meet until March, can write legislation clarifying how it will work.

Even once the kinks in the law get ironed out, activists face a big challenge in getting newly enfranchised Floridians to vote. Since 2007, of the people who went to prison for a felony offense and then got their voting rights restored, only 14 percent have registered to vote, according to an estimate from the Brennan Center for Justice (the estimate does not include people convicted of a felony and sentenced to parole or probation instead of prison).

The Florida Rights Restoration Coalition, the group that pushed for the amendment, is planning a robust voter education effort to make sure that newly enfranchised Floridians exercise their right to vote.

Now that Florida’s new policy has gone into effect, the three remaining states that permanently disenfranchise people with felony convictions are Iowa, Kentucky and Virginia.

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