Kaine Says Top Priority This Year Is Va. Budget

At a Democratic fundraiser last month, Kaine vowed that he would campaign this fall as if his name were on the ballot.

Larry Sabato, a political science professor at the University of Virginia, said Kaine's standing on the national stage will now also be judged on whether he can deliver Virginia for the Democrats this fall.

"With any new position, there are risks and rewards, and one of the big risks here is he won't be able to deliver his state," Sabato said. "Much of his legacy is his political accomplishments, and his political legacy will be damaged" if a Republican wins the governor's mansion.

Three Democrats are vying for the nomination to face Robert F. McDonnell, the popular attorney general and likely GOP candidate.

But Kaine's new role may hamper Democrats' ability to win the governor's race. Since Warner won the governor's mansion in 2001, Virginia Democrats have succeeded by largely distancing themselves from the national party.

Because Kaine now represents the national party -- including Obama and the Democratic-controlled Congress -- Republicans say it will be far harder for the eventual Democratic nominee to separate himself from events in Washington.

"We have lost some elections, but they have been because Democrats were claiming to be centrist," Griffith said. "This makes it easier for us to say, 'Look, he is a national Democrat.' "