For his part, the president, trailing slightly in polls, told battleground state voters that when it comes to choosing a president, "results matter."

Leaving the warm embrace of his most fervent supporters the thousands who flocked to the Democratic Party's nominating convention Kerry is in stronger shape than any presidential challenger in a quarter-century.

After accepting his party's nomination in a boisterous Thursday night convention finale, Kerry and his running mate John Edwards were embarking yesterday on a 3,500-mile, coast-to-coast campaign swing through 21 states.

With slightly more than three months until the election, Kerry is virtually tied with Bush and likely to enjoy a bounce in the polls from this week's convention.

Kerry hit hard at the president's handling of the Iraq war and the war on terror in his acceptance speech Thursday night.

"Saying there are weapons of mass destruction in Iraq doesn't make it so. Saying we can fight a war on the cheap doesn't make it so," Kerry told an overflowing FleetCenter crowd and a television audience of millions.

"And proclaiming mission accomplished certainly doesn't make it so," he said to roars.

Republicans hope to counter any upswing for Kerry by casting Bush as a can-do leader and convincing voters that Kerry has not earned the right to be commander in chief.

Beginning a two-day swing through four presidential battlegrounds after a week's vacation at his Texas ranch, Bush planned to say in a new stump speech that, "When it comes to choosing a president, results matter," according to excerpts of the speech obtained by The Associated Press.

Aides said that was meant to be a subtle suggestion that Kerry has not produced much in his two decades in the Senate.

The Democrats' convention, a four-day show of unity behind Kerry, was designed to tell millions of undecided voters in key states about his Vietnam War service and persuade them that he is prepared to lead and defend the country in an age of terrorism.

Thirteen men who served with Kerry on swiftboats three decades ago in the Mekong Delta shared his spotlight, and a 9 1/2-minute biographical film featured Kerry's own war footage.

Polls show Bush losing public support on Iraq, dropping to 42 percent earlier this month from 59 percent six months ago, according to a Pew Research Center survey.

Kerry, referring to critics' claims that the president's decision to invade Iraq was based on faulty evidence, promised immediate reforms of the US intelligence system so "policy is guided by facts, and facts are never distorted by politics."

He expanded his criticism far beyond Iraq as he sought to draw a contrast with the president on the national security issues he has placed at the core of his challenge for the White House.

Kerry vowed to reverse policies that send US jobs overseas and promised to expand health care, improve education and "fight a smarter, more effective war" against terror.

"In these dangerous days there is a right way and a wrong way to be strong," he said. "Strength is more than tough words."

When he cited US job losses, rising health care costs, pollution and homelessness under Bush, Kerry repeated the phrase: "America can do better. And help is on the way."

Republicans said he has taken inconsistent positions on the war against terror, and that he should explain himself.

Kerry voted in 2002 for the congressional resolution authorizing the use of force in Iraq, but then voted against providing $87 billion for US troops and reconstruction.

"John Kerry missed an opportunity to help the American people understand his vote for the war in Iraq based on the same intelligence that the president viewed," Bush campaign chairman Marc Racicot said. "He's right, America can do better."

As the Democratic nominee, Kerry gets $75 million in public money for the general campaign, the only money he can spend through Nov. 2. Bush, who had $64 million on hand at the beginning of July, gets his $75 million in taxpayer dollars in early September.