By David Espo
The Associated Press

Sen. John Kerry opened his speech Thursday by saluting and saying "I'm John Kerry and I'm reporting for duty." The Associated Press/STEPHEN SAVOIA

BOSTON - Sen. John Kerry challenged President Bush's Iraq policy in blunt, biting terms Thursday night and promised cheering Democratic National Convention delegates, "I will be a commander in chief who will never mislead us into war."

"America can do better, and help is on the way," the Democratic presidential nominee vowed over and over in a prime-time acceptance speech that marked the beginning of the general election phase of his long quest for the White House.

"Saying there are weapons of mass destruction in Iraq doesn't make it so," said the four-term Massachusetts senator, a decorated Vietnam War veteran battling an incumbent president in an age of terrorism.

"Saying we can fight a war on the cheap doesn't make it so. And proclaiming mission accomplished certainly doesn't make it so," Kerry told thousands of delegates packed into an overheated, overcrowded FleetCenter.

2004 DEMOCRATIC NATIONAL CONVENTION

• America can do better, Kerry says • Text of John Kerry's acceptance speech • Pollster finds Kerry a hit with 'swings' • Delegates promise immediate Ohio blitz • Crew tells the nation about 'Nam exploits • Notes from Boston • Multimedia: Democratic convention • Gannett News Service convention coverage • Enquirer's election section

A nationwide television audience of millions also watched.

The hall erupted in cheers as Kerry completed his speech with a promise that, "Our best days are still to come," and the ovation grew louder when running mate John Edwards joined Kerry on the podium, followed by their wives and children.

Moments later, tens of thousands of red, white and blue balloons and strips of confetti beyond counting floated gently to the floor.

An hour earlier, the 60-year-old lawmaker made a triumphant entrance into the hall for the most important speech of his political life, walking a happy gantlet of delegates who reached out eagerly to greet him. "I'm John Kerry and I'm reporting for duty," he said moments later from the podium - and snapped off a salute.

In a speech salted with frequent references to patriotism and service, Kerry said the American flag doesn't "belong to any president. It doesn't belong to any ideology, and it doesn't belong to any political party. It belongs to all the American people."

The Democratic challenger's speech capped a four-day convention designed to persuade millions of undecided voters in the battleground states that he is a man tested by war and ready to assume command.

On the last evening, as on all others, nothing was left to chance - from a new campaign video designed to show Kerry's softer side to a brief tribute from fellow Vietnam veteran Jim Rassmann.

"John Kerry saved my life," he said simply.

Eager to strike out from their convention city, Kerry and vice presidential running mate John Edwards depart today for a 3,500-mile, coast-to-coast campaign swing through 21 states.

After spending the week at his Texas ranch, Bush will resume campaigning this weekend with a bus tour of battleground states and a new message. "We have turned the corner, and we are not turning back," he says in a new stump speech, excerpts of which were obtained by The Associated Press.

Kerry began the week tied or slightly ahead of Bush in the polls, a strong position for a challenger. Whatever sort of surge in support he receives from four days of his highly choreographed convention, Republicans hope to counter next month when they meet in New York to nominate Bush and Vice President Dick Cheney for re-election.

In his speech, Kerry painted a portrait of a nation suffering economically after four years of Republican rule.

"Wages are falling, health-care costs are rising and our great middle class is shrinking. People are working weekends; they're working two jobs, three jobs and they're still not getting ahead," he said.

"We can do better, and we will. We're the optimists," he said, and added, "We value an America where the middle class is not being squeezed, but doing better."

Kerry's decision to question the president over Iraq comes at a time when Bush is struggling to reverse a decline in support for his policies in a conflict that has claimed more than 900 lives.

A Pew Research Center survey this month showed 42 percent support for Bush on the war, down from 59 percent six months earlier.