WASHINGTON - Hillary Clinton may be focused on the final six contests of the Democratic race but front-runner Barack Obama is already moving on.

With the Democratic nomination close to settled, Obama is all but ignoring Clinton and turning his attention to key states in the fight for the White House this fall against Republican John McCain.

Clinton has vowed to keep going through the last votes on June 3, toning down her attacks on Obama while continuing to highlight her ability to attract crucial white blue-collar voters.

There's widespread speculation she may be angling to be his running mate - a dream team for some Democratic power brokers intent on uniting the party after a long divisive battle.

Others see it as a problematic union, with Clinton perhaps demanding a major portfolio and her husband Bill along for the ride.

Top Clinton aide Howard Wolfson said Sunday he's seen "no evidence of her interest" in the job, and others have denied there's been any discussion about the vice-president's position or help on retiring her campaign debt.

Obama, though, has been careful to say she'd be on anybody's list.

"Obviously, I'd want to have a broad-ranging discussion with Senator Clinton about how I could make her feel good about the process and have her on the team moving forward," he said on the weekend.

Obama began his post-primary pitch in earnest Monday after acknowledging Clinton will likely beat him in Tuesday's vote in West Virginia, where she's favoured by a huge margin.

He spent most of his time emphasizing his patriotism and support for veterans in a bid to quell criticism of his allegiance given his longtime opposition to the Iraq war, lack of military service and McCain's status as a Vietnam hero.

Obama even sported a flag lapel pin, something he hasn't worn in the past.

"At a time when we're facing the largest homecoming since the Second World War, the true test of our patriotism is whether we will serve our returning heroes as well as they've served us," he said in Charleston, W. Va.

"We know that over the last eight years we've already fallen short of meeting this test," said Obama, who proposed more benefits for veterans for health care, education, housing and psychiatric treatment.

Obama has routinely been portraying McCain's candidacy as a third term for the policies of President George W. Bush.

McCain, meantime, has been taking aim at the first-term Illinois senator's experience while painting him as a tax-and-spend liberal who's soft on national security.

In addition to stops in states that have yet to vote, Obama's campaign also announced trips to Missouri, Michigan and Florida, which Democrats are hoping to take from Republicans in November's general election.

"Our schedule reflects the fact that we are still fighting for votes and delegates in the remaining contests but also that we are going to places that are going to be competitive in the fall," said spokesman Bill Burton.

"John McCain has gone unchallenged for far too long."

Michigan and Florida were penalized by the Democratic party for holding early primaries. No delegates from the two contests, which Clinton won, have been awarded.

Clinton wants them restored. But she still wouldn't be able to catch up to Obama's lead in pledged delegates.

He's also ahead in states won and the popular vote, and recently overtook Clinton in the support of superdelegates - party officials and legislators who will likely decide the race.

The remaining contests include Kentucky, Puerto Rico, Oregon, South Dakota and Montana.

Obama's chief strategist, David Axelrod, said the campaign is "very seriously" considering a suggestion from McCain's camp that the two participate in joint town meetings and debates across the country this summer.

Obama's campaign has also launched a 50-state voter registration drive.