Maryland Attorney General Douglas F. Gansler at a charity event last year. (Photo by Rebecca D'Angelo For the Washington Post)

Maryland Attorney General Douglas F. Gansler, who plans to launch his 2014 campaign for governor next week, offered supporters a preview of his message Thursday with a nearly six-minute video that portrays him as someone who fights for his beliefs.

The video, sent out over Twitter, features testimonials from a pair of Maryland legislators and other Gansler supporters and highlights both his political career and the lacrosse program he launched five years ago for youths in Baltimore.

“Doug will not shy away from any fight,” Del. Keiffer Jr. Mitchell Jr. (D-Baltimore) says in the video. “If it’s right for the people and right for the state of Maryland, he’s going to fight for it.”

Gansler (D), a former state’s attorney in Montgomery County, pledges that he will “restore pride in Maryland” while working to expand jobs, reduce the minority achievement gap in schools, address transportation problems and help the middle-class.

With his announcement Tuesday, Gansler formally joins a competitive race that includes two Democratic contenders: Lt. Gov. Anthony G. Brown and Del. Heather R. Mizeur (Montgomery).

Brown launched his campaign in May, named a running mate in June and has racked up a sizable number of high-profile endorsements since. Sen. Barbara A. Mikulski (D-Md.), who rarely picks sides in Democratic primaries, is slated to become the latest Sunday.

Mizeur, who would be Maryland’s first female governor, announced her campaign in July.

Gansler deliberately held off on his announcement, calculating that he could make a bigger splash after summer when more people started paying attention to the race to succeed Gov. Martin O’Malley (D).

Gansler’s campaign has planned a 17-stop announcement tour that will run more than a week and hit every region of the state.

In the video, Mitchell, among those who have talked to Gansler about being his running mate, says that Gansler has stood up to insurers, gun lobbyists and polluters during his tenure as attorney general.

Sen. Richard S. Madaleno Jr. (D-Montgomery) credits Gansler for changing the dynamic on same-sex marriage in Maryland. Gansler was the first statewide official to endorse its legalization.

“Before Doug came out for marriage equality, people said it would be impossible in the state of Maryland,” says Madaleno, who is gay.

Joseph D. Tydings, a former U.S. senator from Maryland, is among the others who lavishes praise on Gansler, calling him “a born fighter.”