Tampa Bay Mayor Bob Buckhorn announced his endorsement of Democratic gubernatorial candidate Gwen Graham late Thursday afternoon. Endorsements usually don’t carry a lot of political clout. But, Buckhorn is a political force in the Tampa area who has been mentioned as a possible running mate for Graham.

“Over the past seven years, Tampa has entered a new chapter of our city’s history. We’re creating good paying jobs, attracting the best and brightest talent, and working to make Tampa one of the best places to live, work, and raise a family,” Buckhorn said in making the endorsement.

“Now it is time for our state to write its next chapter. We need a governor dedicated to restoring our public schools, protecting our environment and finally expanding health care,” Buckhorn added. “Today, I am proud to endorse Gwen Graham — because I know she will be that governor.”

Buckhorn, 60, is a popular Democrat along the crucial Interstate 4 corridor. He was twice elected mayor and became known as a champion for economic development in the Tampa area. His InVision Tampa plan has worked to diversify the city’s economy and he’s been a vocal opponent to oil drilling in the Gulf of Mexico.

“Mayor Buckhorn has brought Tampa together to move his city forward. As governor, I will work with him and mayors across our state to move every community forward and help every Floridian prosper,” Graham said. “We must invest in our public schools, create good-paying jobs, protect our precious environment and finally expand health care. With all of us working together, we can and will get it done.”

While he announced his formal endorsement today, Buckhorn came out in support of Graham last month and has long been rumored to be a potential lieutenant governor’s candidate on a Graham ticket. Like Graham, Buckhorn is known for being able to work with Republicans, an important asset given that Republicans will likely continue to control the Legislature after the midterm election.

Graham is running in the Democratic primary against former Miami Beach Mayor Philip Levine, Tallahassee Mayor Andrew Gillum, Palm Beach real estate investor Jeff Greene and Winter Park businessman Chris King.

Two recent polls released last week suggested Graham was the front-runner and building a lead in the race. However a poll released Wednesday afternoon showed Levine with a 3-point avantage.