WASHINGTON (CNN) -- Sen. Barack Obama, the presumptive Democratic nominee, kicked off his general election campaign Thursday with stops in Virginia, signaling that he thinks he can turn the once solidly red state into a Democratic pickup come November.
Obama told a crowd in Bristow, Virginia, that going forward, the Democratic National Committee would no longer accept money from federal lobbyists or political action committees.
"We're going to change how Washington works," he said. "They will not fund my party, they will not run our White House, and they will not drown out the voice of the American people."
Obama also praised Sen. Hillary Clinton, calling her an "outstanding candidate."
"I know I'm a better candidate because I ran against her. She's tough. She is just an outstanding candidate and a great public servant," he said.
Clinton on Thursday sent an e-mail to supporters saying she will throw her support to Obama on Saturday.
Obama's day will culminate with an evening rally in northern Virginia, where Sen. Jim Webb, often mentioned as a possible vice presidential candidate, will make his first campaign appearance with Obama.
Virginia hasn't voted for a Democrat since President Lyndon B. Johnson in 1964, but for more than a year, Obama's campaign has cited the state's 13 electoral votes as part of its argument that he can reshuffle the electoral map this fall. Obama spokesman Tommy Vietor said Virginia will play a "pivotal role" in the general election.
Political campaigns in the state hinge on the prosperous northern suburbs, and Obama's schedulers are aware of the region's significance: His first major campaign event since clinching the nomination will be a rally Thursday evening at Nissan Pavilion, a 25,000-seat concert venue in Bristow that in recent weeks has hosted such acts as Radiohead and Kanye West. iReport.com: See one cartoonist's take on Obama
"Clearly, Obama believes Virginia can be very competitive, and northern Virginia is the place where Democrats really have transformed their vote, ringing up far heavier majorities in northern Virginia than previously," said Robert D. Holsworth, a political scientist at Virginia Commonwealth University in Richmond.
However, Obama's stop in Bristol, a town on the Tennessee border, might be just as crucial. He's attempting to make up ground in rural southwest Virginia, a region he lost handily in his otherwise resounding win on February 12.
Obama won the Virginia primary 64 percent to 35 percent, but he lost to Clinton in the 9th Congressional District by 33 percentage points, one of the first signs of a pattern of vulnerability among white working-class voters that continued to nag him through primaries in Ohio, Pennsylvania and West Virginia.
David "Mudcat" Saunders, a Roanoke-based strategist who has advised politicians on how to reach out to rural voters, said southwest Virginia is "a logical place" for Obama to start because he will need to appeal to those voters in other crucial battleground states as well.
"If Virginia truly is in play, it's a practical move for him because he can get the western Pennsylvania bunch, the southeast Ohio bunch," Saunders said. "It's the same region. It's the same bunch of people; they just live in different states."
He added, "These are the people around the country who decide the president of the United States, and they are neglected. The Republicans take them for granted, and the Democrats don't try to come get 'em. God bless Barack Obama for trying to go get 'em." Watch why Obama represents a symbol of change »
The three Democrats who have won statewide races in recent years -- Webb, Gov. Tim Kaine and former Gov. Mark Warner -- were each elected on the strength of support from liberal and moderate voters in northern Virginia. But each candidate managed to make healthy inroads among Appalachian voters as well.
Saunders noted the 9th District is a "fickle" swing district in general elections. In 2000, for instance, then-GOP Senate candidate George Allen netted 56 percent of the vote to win the election. The next year, Warner, a Democrat, was elected governor with 52 percent of the district's vote. iReport.com: What do you think will decide race?
Warner, the front-runner to replace retiring Sen. John Warner, R-Virginia, will campaign Friday with Obama in Bristol.
Kaine, one of the first prominent Democratic leaders to endorse Obama last year, will appear briefly with the presumptive nominee at the Bristow rally in northern Virginia. All three Virginia Democrats have been mentioned as possible vice presidential candidates for Obama.
But Virginia remains a challenge for the Democratic nominee, especially against Sen. John McCain, who appeals not only to mainline Republicans but also with independents and military voters and veterans.
"McCain doesn't have the loyalty among a lot of conservatives nationwide," Holsworth said, "but he is a pretty good candidate for Virginia. Virginia gets a lot of defense money, and his personal biography and his support for the military will make him a very strong candidate here."
McCain will hold a fundraiser Monday in Richmond.
Republican delegate Chris Saxman, co-chair of McCain's campaign in the state, dismissed Obama's chances of winning Virginia on a conference call organized by the Republican National Committee.
Summing up what he called Obama's positions, Saxman said: "'I don't like guns. I'm going to raise your taxes. I don't like coal.' That's a tough sell in Virginia."
CNN's Chris Welch contributed to this report.