Andrew Gillum is launching a massive voter registration effort aimed at ensuring that President Trump doesn’t win Florida again in 2020 and to give Democrats a decisive edge in a state where elections are often 50-50 splits.

The 39-year-old Democrat and former Tallahassee mayor plans to use the list of supporters and volunteers he amassed in his razor-thin gubernatorial defeat in 2018 to register 1 million new voters before next year’s presidential election.

“We’re going to be a major player and deliver Florida to whoever the Democratic nominee is,” he told The Daily Beast before his announcement in Miami Gardens on Wednesday evening. “I firmly believe that Florida is not a red state, it’s not a purple state. It’s an unorganized state.”

His supporters registered a new group in advance of his announcement called Bring It Home Florida, named after a commonly used phrase from his campaign. While Gillum did not say exactly how much they intend to spend on the effort, he characterized it as one of the largest voter registration investments in history. His political action committee, Forward Florida, has nearly $3.9 million at its disposal. This is in addition to a plan from the state party to spend $2 million on voter registration.

Gillum saw firsthand in the 2018 gubernatorial election just how close the perennial swing state’s elections can get. He came up short of Republican Ron DeSantis by less than 33,000 votes out of more than 8 million cast. It was the closest gubernatorial election in the state’s history. Democrats think adding another million voters to the pool could have made a difference in his race and any future state or federal races for the party.

Democrats are also concerned about the drop-off in voter registration advantages for the party in the state. Steve Schale, the Florida state director for Barack Obama’s 2008 campaign, estimated that the party has seen its voter registration advantage drop by 400,000 voters over the last ten years.

“I think it’s vital. I think there’s a pretty fair argument that Barack Obama doesn’t win in ’08 or ’12 without significant voter registration efforts,” he said. “And at the same time does Andrew Gillum win the election in 2018 if the voter makeup of the state, from a partisan standpoint, looks like it did in ’08 or ’12? Probably does.”

While Gillum’s efforts are limited to Florida, they come as Democrats nationwide have focused more intensely on voting rights and state elections. Stacey Abrams, the 2018 Democratic gubernatorial candidate in Georgia, launched Fair Fight Action to focus on reforming elections and combating voter suppression. Eric Holder, the former attorney general, passed on a presidential run to continue his work against gerrymandering around the country.

Gillum said he plans to use his base of tens of thousands of volunteers, over 1 million cellphone numbers, and just under a million email addresses to mobilize a grassroots effort to find these voters and make sure they’re registered. The massive effort will not only involve door-to-door canvassing but reaching people digitally where they’re legally able to register in the state.

As Gillum tries to expand voting in Florida, some Republicans are trying to constrict it.

In 2018, voters overwhelmingly passed a constitutional amendment to allow former felons to vote. On Tuesday, the day before Gillum’s announcement, a subcommittee in the state’s Republican-controlled legislature voted to require former felons to pay outstanding fines and fees before regaining their right to vote.

Gillum hasn’t said if he plans to run for public office again, but delivering the White House to a Democrat in 2020 wouldn’t be a bad launching point.

“We will do the work that is necessary to help get these folks registered, but it will still be up to a good candidate to talk about the issues that are going to animate those voters to get to the polls,” he said. “We want a winning showing come November.”