Updated

Republican U.S. Sen. David Vitter will be a candidate in Louisiana's 2015 governor's race, announcing his decision Tuesday in an email to supporters.

"I believe that as our next Governor, I can have a bigger impact addressing the unique challenges and opportunities we face in Louisiana," the senator said in an email obtained by The Associated Press from a member of Vitter's staff.

Vitter's announcement ends months of speculation about his intentions, and his decision is expected to influence which other potential candidates enter the race.

Gov. Bobby Jindal is term-limited, so the race is wide open. Vitter can run without forfeiting his current position in the U.S. Senate, which isn't up for re-election until 2016.

In a preview outline of his priorities if he becomes governor, Vitter said he'll push for excellence in education, budget stability, tax and spending reform and government accountability.

"This will be my last political job, elected or appointed, period. So my only agenda will be to do what's best for all Louisianians, from our best and brightest to our most vulnerable," he says in the email, which also announces Vitter's campaign website.

Others who have said they will run for governor include: Republican Lt. Gov. Jay Dardenne and state Rep. John Bel Edwards, chairman of the House Democratic Caucus. GOP Treasurer John Kennedy also has said he is considering entering the race.

Vitter's approval ratings are high in Louisiana, and his ability to rake in campaign donations is strong. Already, the leader of a pro-Vitter super PAC said the organization has raised $1.5 million to support a gubernatorial run for the senator.

"Although an active campaign is still a year away, I'll start preparing for it immediately by doing what I've always done, including as our U.S. Senator. That's listening to you, knowing that I sure don't have all the answers," Vitter says to supporters in his e-mail.

He has proved to be a resilient politician, holding elected office for more than two decades as a state and federal lawmaker and easily winning re-election to a second U.S. Senate term in 2010, despite a prostitution scandal.

Vitter admitted to a "serious sin" after phone records linked him to Washington's "D.C. Madam" prostitution case in 2007, but he's never commented further on whether he broke the law, instead saying his family had forgiven him and moved past it.

Voters don't appear to hold the scandal against Vitter, with more than 58 percent giving him good marks in a recent Southern Media and Opinion Research poll about his job performance.