Kerry had just returned from serving as a Navy lieutenant in Vietnam, where he had been awarded two citations for heroism and three medals for wounds suffered in battle. He had volunteered to serve in Southeast Asia, believing that it was his duty as the well-traveled, well-educated son of a prosperous diplomat.
But his attitudes changed dramatically in Vietnam. He saw his friends and colleagues dying in a war that he believed was being run by politicians more concerned with salvaging their reputations than promoting democracy in Southeast Asia.
On his return home, Kerry became a spokesman for the Vietnam Veterans Against the War, and brought the group's message to the American people during testimony before the Senate Foreign Relations Committee in Washington in 1972.
Kerry summarized his feelings -- and those of millions of other Americans -- with two questions: "How do you ask a man to be the last man to die in Vietnam? How do you ask a man to be the last man to die for a mistake?"
One of the senators at that hearing, Democrat Claiborne Pell, praised Kerry's combination of passion and restraint, and told him he hoped the witness would one day become a senator himself. That would happen 13 years later. He was even mentioned as a future candidate for president.
Following his congressional testimony, Kerry ran for a seat in the U.S. Congress in 1972, but lost. Stung by the defeat, he went to law school, and from there became a prosecutor in northeastern Massachusetts, his native state. He gained a reputation for improving the organization of the prosecutor's office, and for successfully fighting organized crime.
Soon, Kerry became a private lawyer, and in 1982 successfully ran for elective office, becoming the lieutenant governor of Massachusetts. Again, he showed a talent for organization, and two years later won one of the state's two seats in the U.S. Senate. He is now serving his fourth Senate term.
In the Senate, Kerry has voted in favor of government support of public health insurance for the poor, improved public education and bills supported by the nation's leading environmental advocacy groups. And he has served on the Foreign Relations, Armed Services, and Intelligence committees, the most prestigious in the Senate.
In his campaign for president, Kerry has drawn on his background as a war hero, an effective prosecutor, and as a senator with a broad world view. He fought off challenges from former Vermont Governor Howard Dean and fellow U.S. Senator John Edwards, as well as five other candidates. He won enough delegates to his party's convention to ensure that he would win the Democratic Party's nomination.
Bush's handling of the war in Iraq and the battle against terrorism have become key issues in the campaign. Kerry says Bush did not exhaust all diplomatic alternatives before the U.S.-led invasion of Iraq in March 2003. And he accuses Bush of making Americans more vulnerable to attacks by Al-Qaeda and similar groups by diverting security resources to Iraq.
Kerry described Bush's conduct of the war this way in a speech four months ago in Washington. "We were misled about weapons of mass destruction. We were misled, in very specific terms, about the evidence that we were shown within those briefings to the Congress of the United States, and we are misled now when the costs of Iraq are not even counted in the president's budget," Kerry said.
Yet, Kerry voted in favor the congressional resolution that authorized Bush to use force against Iraq if necessary, and Bush has taken advantage of that evident contradiction. In fact, during much of the presidential campaign this year, Bush and fellow Republicans have accused Kerry of similar contradictions on other issues.
"The [Democratic Party] candidates are an interesting group with diverse opinions -- for tax cuts and against them, for NAFTA [North American Free Trade Agreement] and against NAFTA, for the Patriot Act and against the Patriot Act, in favor of liberating Iraq and opposed to it -- and that is just one senator from Massachusetts," said Bush, speaking in February to an audience of Republican state governors in Washington.
Kerry's supporters say he is a deep thinker who doesn't see the world in absolute terms, as they say Bush does. Kerry says he voted to give Bush the power to wage war against Iraq in an effort to strengthen diplomatic leverage against former Iraqi President Saddam Hussein.
Polls show that Kerry and Bush have about the same percentage of support among voters, meaning that at this stage of the campaign, Kerry is doing far better than previous presidential challengers have done in recent history. They also show that most Democrats are united behind Kerry.
But a significant number of Americans say they are undecided about whom they'll support in the 2 November election. There are many who say they are disappointed in Bush but are not inspired by Kerry.
On the evening of 29 July, it will be up to Kerry to persuade these undecided voters that he is not just a brave soldier and a well-organized prosecutor. He must show them that he is a strong leader, not the inconsistent legislator portrayed by Bush.