Washington (CNN) - Democratic National Committee Chairman and former Virginia Gov. Tim Kaine ended weeks of speculation Tuesday by announcing that he will seek his state's open Senate seat, which is being vacated by Sen. Jim Webb.
Webb, a Democrat, announced his retirement in February.
Kaine made the announcement in a video posted on his new campaign website, focusing on his record as governor that "made government more efficient" through budget cuts and investments in education and transportation.
"While we still have an awful lot of work to do to help Virginians who are struggling through a tough time, I know that Washington can learn a few things from Virginia," Kaine says in the video, which makes no mention of his tenure at the DNC or his close ties to President Barack Obama.
Kaine has a pre-scheduled speech Wednesday on economic policy at the University of Richmond, which will be followed by a press conference. A more formal campaign announcement will come later.
If former Sen. George Allen manages to win the Republican nomination - and there's no guarantee that he will in a primary against one or more conservative opponents - the race would be a battle between two of the commonwealth's political titans, pitting one former governor against another. Allen was governor from 1994 to 1998.
Kaine, too, has a long resume in Virginia politics, having served as mayor of Richmond, lieutenant governor and then governor from 2006 to 2010. He was one of the first prominent Democrats to endorse Barack Obama after he announced his White House run and remains close to the president.
The White House sees Virginia – a state Obama won in 2008 - as key to the president's re-election chances and wants a tested campaigner on the ballot alongside him.
But Republicans argue that Kaine's vocal support of some of the Obama administration's more controversial policies over his two years as DNC Chairman makes him vulnerable in a state with decidedly moderate political tendencies.
Republican Party of Virginia chairman Pat Mullins painted Kaine as big-spending liberal in a statement Tuesday.
"For the past two years Tim Kaine has been President Obama's biggest advocate in Washington," Mullins said. "From the failed stimulus packages, to the budget busting spending bills that have increased our national debt at record levels, Tim Kaine has been there every step of the way making the case for a bigger and more intrusive federal government."
An adviser to Kaine welcomed the debate.
"Tim Kaine has a long record working for the people of Virginia, pushing fiscally responsible measures as governor, cutting the state budget, working across the aisle and seeing Virginia named the best-managed state in the nation," the adviser said. "If they want to compare that record with the other side, which supported policies that took largest surplus in American history and turned it into largest deficit, we are happy to have that argument."
Kaine departure from the DNC means that the White House has a high-profile job to fill as the president ramps up his re-election effort for 2012.
Former Ohio Gov. Ted Strickland and Florida Rep. Debbie Wasserman-Schultz are two of the top contenders for the job, though other Democrats could be in the mix.