On Nov. 6, Florida voters could approve an amendment that would significantly affect the voting population of one of the most crucial swing states in the country. Amendment 4 is one of 13 ballot initiatives that Floridians are considering this year, but it has received the most national attention, as it would enfranchise the largest population in U.S. history since women's suffrage.

The measure would reconstitute the right of felons to vote after they complete their sentences. Florida is the third-largest state in the country by population, and has the highest number of people disenfranchised by prior felony convictions -- around 1.5 million people there are prevented from voting due to their criminal record.

With its 29 electoral college votes and perennial swing-state status, Florida is also tremendously influential politically. It was the deciding state in the 2000 election, and one of the most important ones in the 2016 election.

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According to the Florida state department, roughly 13 million citizens are registered to vote, with both Republicans and Democrats having nearly 5 million party members each. If another million people are added to the voter rolls, it could affect the balance of power in a state largely controlled by Republicans on the state level.

As black people are disproportionately represented among former felons, one in five black Florida voters are prohibited from voting due to a criminal record. Although they make up only 16 percent of the population according to the 2010 Census, black people make up 43 percent of Florida's inmate population, according to the latest yearly report from the Florida Department of Corrections. Florida also accounts for a quarter of the disenfranchised population in the United States, according to the Sentencing Project.

Black voters are not guaranteed additions to the Democratic Party, but the party in general has a higher number of black voters than the Republican Party. In 2018, there are two extremely close statewide races, one for governor and one for U.S. Senate. Although the ballot measure wouldn't affect any races this year, it could change the outcome similarly competitive races in the future.

Florida is one of four states that disenfranchises former felons, unless a state official or board restores an individual's rights. The other states are Kentucky, Iowa and Virginia. The exception to the amendment re-enfranchising felons are those convicted of murder and sexual offenses, who would remain ineligible.

The amendment, which needs a 60 percent majority to be added to the state constitution, has widespread support across the state. Two polls from the spring showed that over 70 percent of voters support Amendment 4, including majorities of both Democrats and Republicans. However, a June poll from the Florida Chamber of Commerce -- which activists say did not explain the substance of the poll to respondents -- showed 40 percent support, with 43 percent undecided.

The campaign supporting the passage of the amendment appears stronger than the campaign against it. A committee registered in support of the amendment, Floridians for a Fair Democracy, has raised over $15 million. The American Civil Liberties Union has provided $5 million for that campaign.

Support for the initiative is bipartisan -- Freedom Partners, a right-leaning group backed by the influential Koch brothers, has endorsed the amendment. Opposition to the campaign is minimal, although some conservatives are against it, as well as criminal justice activists who believe voting rights should extend also to felons convicted of murder and sex offenses.

With widespread support and little public opposition, Amendment 4 could be poised for approval this November, potentially shifting politics in Florida in ways that could have a national impact.