ORLANDO, Fla. — The mayors of Central Florida’s three largest cities are officially supporting democrat Andrew Gillum in his bid to become Florida’s next governor.

Mayors Buddy Dyer (Orlando), Bob Buckhorn (Tampa), and Rick Kriseman (St. Petersburg) gathered Thursday morning in downtown Orlando to make the announcement.

The trio were among those who first supported Gillum’s primary opponent, Gwen Graham, but have now reversed course.

The I-4 mayors sang Gillum’s praise Thursday, based on his mayoral experience.

“I think his vision and his leadership skills are the most important,” Orlando Mayor Buddy Dyer said. “We need to have a governor who respects local government and making our communities stronger is so important to us, and Mayor Gillum has a vision for this state to put the people first.”

“It is the cities of Florida that are making a difference in this state,” Tampa Mayor Bob Buckhorn said. “Mayors matter. What matters to us is that we have a partner in the governor’s office. What matters to us that we stop this unrelenting assault on local government. I need a governor who is going to pay more attention to the PTA and less attention to the NRA.”

With running mate Chris King by his side, Andrew Gillum highlighted a series of issues with supporters Thursday. Including high-tech job training, economy, education, transportation, and health care.

Gillum says he wants to expand Medicaid in Florida if elected.

“The priority is to expand Medicaid here in the State of Florida,” Gillum said. “We have 800,000 people, among the most medically needy in this state, who don’t have access to healthcare. When we expand Medicaid, we’re going to pull down $6 billion from the federal government that today is money being distributed to other states because we failed to do that.”

Gillum also criticized Gov. Rick Scott for a decision in 2011 to reject $2 billion in federal money to build a high speed rail system between Orlando and Tampa. Gov. Scott said at the time that it would be too risky for taxpayers. Governor Scott now supports -- and reportedly has investments through his blind trust -- in the parent company of All Aboard Florida, which is operating Brightline, a high speed rail service between West Palm Beach and Miami.

The high speed rail service is under construction to link South Florida to Orlando by the year 2021, with applications submitted to expand the service several years after to Tampa.

I-4 corridor a ‘swing region’

Most polls show whoever wins in November will do so by a narrow victory.

“The I-4 corridor always has the reputation of being the biggest political battle ground in the country, and that’s because it’s the swing region of the swing state,” said Frank Torres, Spectrum News Political Analyst. “It’s what separates more progressive South Florida from more conservative North Florida.”

Interstate 4 becomes the dividing line of those counties.

There are more than 2.3 million registered voters in Orange, Hillsborough, and Pinellas counties. Nearly a third, approximately 682,267 voters are registered as ‘No Party Affiliation.’

Torres says the endorsements of Dyer, Buckhorn, and Kriseman could influence a few undecided voters who view their respective mayors favorably.

The campaigns still have to steer through a clutter of negative attack ads on television, radio, and the internet.

The candidates for Florida governor have agreed to at least two debates – the first on October 16, hosted by Spanish language network Telemundo in Orlando, and a second debate on October 24 in Broward County.