US Senator John Kerry sealed the Democratic nomination to take on George W Bush for the White House in November by winning the presidential primary in Illinois.
Mr Kerry's unsurprising victory last night boosted his delegate count to at least 2,252, well past the 2,162 needed to secure the nomination at the Democratic convention in July.
Mr Kerry promised to be a "veteran's veteran" as the White House tried to sour his support among a key constituency by airing a commercial accusing him of rejecting funding for soldiers at war in Iraq.
He warned an audience of veterans that President Bush has misled the country on everything from the war to the economy and had broken promises to veterans needing health care.
From the Oval Office yesterday, Mr Bush questioned his rival's own truthfulness by calling for him to identify the world leaders Mr Kerry has said would rather see him as president.
In his first visit to West Virginia since becoming the presumptive Democratic presidential nominee, Mr Kerry was seeking to define himself as a war hero.
The state has 203,000 veterans, or 15.4% of its adult population. Although solidly Democratic in past elections, West Virginia sided with Mr Bush instead of Al Gore in 2000.
Its five electoral votes would be essential in another close election.
"Nothing is more important than telling the American people the truth about the economy, health care, and war and peace," Mr Kerry told veterans in Huntington. "This administration has yet to level with the American people."
Although Mr Kerry has said he would not break confidences and reveal which overseas leaders have told him they back his campaign, Mr Bush told reporters: "If you're going to make an accusation in the course of a presidential campaign, you ought to back it up with facts."
For the second day in a row, Vice President Dick Cheney criticised Mr Kerry at a Republican fund-raiser. "We are the ones who get to determine the outcome of this election, not unnamed foreign leaders," Mr Cheney said.
Joining Mr Kerry in Huntington were seven members of swift boats he commanded in Vietnam, service that won the senator three Purple Hearts, a Bronze Star and a Silver Star.
At the same time, the Bush campaign released a television ad accusing Mr Kerry of being "wrong on defence" by not supporting bills that would have ensured troops had body armour and higher combat pay and given reservists and their families better health care.
"Few votes in Congress are as important as funding our troops at war. Though John Kerry voted in October of 2002 for military action in Iraq, he later voted against funding our soldiers," the ad says.
Mr Kerry labelled the ad "another distortion" arguing that he would have supported funding for the troops if Mr Bush had eased his tax cut to avoid exploding the deficit.
He also attacked Mr Bush's handling of the economy, pointing to a Congressional Budget Office study that said only 6% of the nation's deficit can be attributed to cyclical economic issues.