Andrew Gillum, the mayor of Tallahassee, became the first entrant in Florida's 2018 race for governor Wednesday. Gillum announced his candidacy in an online video that drew the immediate ire of Republicans.

The 37-year-old mayor has built a profile as an up-and-coming African-American leader -- precisely the background some Democratic activists argue their nominee will need in order for the party to capture the governor's mansion for the first time in nearly a quarter-century.

And Gillum's message is a timely one, with his pledge to lift up Floridians who have been left behind as income inequality has expanded.

"I can't wait to be able to move forward a vision in this state that puts people to work at every rung on the income ladder," Gillum said in the video. "That's what I want to do for the state of Florida."

Within hours of the video's release, the Republican Governors Association was on the attack, accusing Gillum of "playing fast and loose with election law" by allegedly using a taxpayer-funded software system to send campaign emails to his supporters.

"After just one day on the campaign trail, Andrew Gillum has already shown an inexcusable disregard for Florida's election and campaign finance laws," the association said in a statement. "Florida's next governor should be someone who will uphold the rule of law and uphold the public's trust in its elected leaders. Andrew Gillum has already failed that test."

The association is co-chaired by Gov. Rick Scott, who has frequently locked horns with Gillum over the mayor's handling of Tallahassee's municipally-owned utility.

Gillum could also face challenges from within his own party. Despite delivering an address before a national audience at last year's Democratic National Convention, he remains little known outside Tallahassee.

Tampa Mayor Bob Buckhorn, Miami Beach Mayor Philip Levine, former U.S. Rep. Gwen Graham and Orlando power attorney John Morgan are all considering their own gubernatorial bids and enjoy significant advantages over Gillum in fundraising prowess and name recognition.

The potential for a crowded field could explain the timing of Gillum's announcement, roughly 18 months before the Democratic gubernatorial primary election, as well as his decision to staff up well ahead of a typical campaign's schedule. The mayor has hired Geoff Burgan, a Democratic political operative who has worked for U.S. Rep. Debbie Wasserman Schultz and former Maryland Gov. Martin O'Malley, as his campaign spokesman.

"In six months' time or in a year's time, who knows who would have announced -- if it was John Morgan or Gwen Graham, to solidify her interest in running," said Tallahassee political consultant Trimmel Gomes. "So, jumping out first is really getting all of the attention. Everyone's looking at him."

That attention, as evidenced by the first day of Gillum's campaign, cuts both ways. As he works to build up his statewide profile, Republicans are already working to undercut it, and a cast of potential Democratic rivals may not be far behind.

We've embedded Gillum's video below. If you don't see it, click here.