Washington (CNN) A federal appeals court on Wednesday upheld a ruling giving Florida ex-felons the right to vote regardless of fines and fees associated with their convictions.

The 11th Circuit Court of Appeals, affirming a district court's previous decision, said a Republican-led effort to require ex-felons to pay up before they can vote -- a requirement that in some cases could cost individuals thousands of dollars -- violates the Equal Protection Clause.

"Here, the plaintiffs are not punished in proportion to their culpability but to their wealth -- equally guilty but wealthier felons are offered access to the ballot while these plaintiffs continue to be disenfranchised, perhaps forever," the court said in its decision.

The practical effect of the 11th circuit's decision is unclear, and Republican Gov. Ron DeSantis plans to appeal, a spokeswoman said. The registration deadline to vote in the state's presidential primaries was on Tuesday , and the legal and legislative challenges that have been launched since voters gave ex-felons the right to vote in a 2018 referendum could prevent many of them from participating in November's general election.

But the decision was hailed by voting rights groups, including the Southern Poverty Law Center, which represented two plaintiffs in the case.

"The Eleventh Circuit today affirmed what we knew all along: the right to vote of our clients, Rosemary McCoy and Sheila Singleton, cannot be conditioned on their wealth," Nancy Abudu, deputy legal director for the Southern Poverty Law Center, said in a press release.

Wednesday's ruling, which sends the case back to district court, is the latest twist in a long-running fight over re-enfranchising about 1.4 million Floridians who had previously lost their voting rights due to felony convictions.

In November 2018, Florida voters approved a constitutional amendment allowing convicted felons who complete all terms of their sentence, including parole or probation, the right to vote, except those convicted of murder or a felony sexual offense. Amendment 4 passed with nearly 65% of the vote, exceeding the 60% threshold required to become a law.

The addition of so many new voters could have a profound impact in a place where statewide contests are often decided by slim margins. An analysis conducted in 2018 by the Tampa Bay Times and Miami Herald found Democratic and black voters were far more likely to have lost their voting rights because of a felony conviction, and in the same election that approved the referendum, Democratic US Sen. Bill Nelson was ousted by Republican Rick Scott by a little over 10,000 votes. In 2016 , Donald Trump captured the Sunshine State by less than 113,000 votes over Hillary Clinton, or 1.2% of the vote.

Soon after the referendum was passed, Republicans, including DeSantis, said the law was unclear as to how it should be implemented and what constitutes the completion of a sentence. They argued that the fines and fees are part of an ex-felon's sentence and are thus obligatory, but Democrats said the effort is an attempt to institute a modern-day "poll tax" to prevent ex-felons from voting.

Last May, DeSantis signed into law a bill that required ex-felons to pay all financial obligations before they can vote.

The American Civil Liberties Union -- which says 20% of the black voting age population in Florida has been disenfranchised due to a felony conviction -- has argued that the state has not provided guidance to voters or local election supervisors, having a chilling effect on voters with a conviction who fear prosecution.

The fees and fines that felons are ordered to pay are wide-ranging but significantly high for an individual leaving prison, especially if they're unemployed. They can range from a couple hundred to tens of thousands of dollars, Lisa Foster, the co-director of the Fines and Fees Justice Center, a group that aims to eliminate fees in the US justice system, has told CNN. And in Florida, all the court charges that are unpaid after 90 days are referred to private debt collectors, who are allowed to add up to a 40% surcharge on the unpaid court debt, according to the Brennan Center

The ACLU says it's up to the state legislature to fix the law by removing the fines and fees requirement for those who cannot afford it. But two top GOP state lawmakers have said they won't revisit how they implemented Amendment 4 and will wait until the US Supreme Court takes up the case, the Tampa Bay Times has reported.

Two of the plaintiffs in Wednesday's case included Rosemary McCoy and Sheila Singleton, two black women and Jacksonville residents with prior felony convictions. McCoy previously told CNN in a phone interview that she owed about $6,000 -- a debt she said she couldn't afford to pay off due to a lack of employment opportunities.

"How can you hold someone hostage and say they cannot vote because they owe this money? There is a difference: there is punishment and then there is restitution. Restitution is not a part of the punishment. We were already punished. Now you are holding us hostage to stop us from voting," McCoy said last month.