WASHINGTON (CNN) -- Former Virginia Gov. Mark Warner, a Democrat, announced his candidacy for the U.S. Senate Thursday with a new campaign Web site and a YouTube video.
Mark Warner announced his candidacy for the Senate on his Web site Thursday.
The site, called MarkWarner2008, features a Web video in which Warner pitches himself as a moderate problem solver willing to work with both Republicans and Democrats -- the same formula that contributed to his popularity as Virginia governor.
"I've decided the way I can contribute most to getting our country back on track is to serve in the United State Senate," Warner said in the video.
Warner also says he will wait to make a formal announcement until after Virginia's legislative elections in November.
The former governor also informed supporters Thursday morning by e-mail about his decision to run for the Senate.
In the 2006 midterm elections, Democrat Jim Webb ousted Republican incumbent Sen. George Allen by a margin of fewer than 10,000 votes, or less than half a percentage point. Webb's victory helped give Democrats a 51-49 Senate majority. We could see an equally close contest in Virginia next year.
Incumbent Republican Sen. John Warner, no relation to Mark Warner, recently announced that he will retire at the end of his current term, concluding 30 years in office.
National Democratic leaders hope that Mark Warner will be their ticket to taking the seat away from the GOP. Warner's term as governor ended in January 2006, and he left office with high favorable ratings. Warner then flirted with running for the White House.
Virginia was once a reliable red state, but Democrats have won three major statewide elections there this decade.
"Virginia has been a reliable Republican state since the 1960s with an occasional Democratic breakthrough," said CNN senior political analyst Bill Schneider. "Now those breakthroughs are becoming more frequent."
On the Republican side, there could be a bitter primary fight between Rep. Tom Davis, a moderate Republican from northern Virginia, and conservative former Gov. Jim Gilmore. Gilmore dropped out of the presidential race earlier this year.
John Warner's retirement makes the GOP's tough task of taking back the Senate next year even tougher. Republican Sens. Chuck Hagel of Nebraska and Wayne Allard of Colorado have also announced that they are retiring rather than running for re-election. The GOP will could face a serious fight to keep both of those seats in Republican hands.
In addition to potentially tough races ahead for them now in Virginia, Nebraska and Colorado, a number of Republican senators up for re-election next year will be fighting for their political lives. The list includes Susan Collins of Maine, John Sununu of New Hampshire, Norm Coleman of Minnesota and Gordon Smith of Oregon. As of now, only one Democrat up next year, Mary Landrieu of Louisiana, appears to be facing a major fight.
And it's not only the numbers that are stacking up against the Republicans.
"You've got an unpopular war, an unpopular president and an overwhelming desire for change. And in a presidential year, the incumbent president's party defines the status quo," said Schneider.
Also hurting Republican candidates are the various scandals and investigations into several of their colleagues. Democrats coined the "culture of corruption" slogan last year as the party successfully wrested control of the House and Senate from Republican hands. They are hoping it works again in 2008.
The most recent sex scandal involving Sen. Larry Craig should not hurt the GOP's chances of holding on to that seat in 2008 if the Idaho Republican does indeed resign from office at the end of the month. At the very least, though, the controversy over his arrest in a Minneapolis airport restroom and subsequent guilty plea is not helping his party one bit. E-mail to a friend
CNN's Peter Hamby and Paul Steinhauser contributed to this report.