The Democratic National Convention, held this week in the FleetCenter in Boston, was capped off when Sen. John F. Kerry, D-Mass., accepted his party's nomination last night.

BOSTON—It was, by general consensus, the most important speech of John F. Kerry’s life.

Speaking to an over-capacity audience of loyal Democrats in the FleetCenter, the Massachusetts senator arrived on stage to accept his party’s nomination for president. But his words were aimed further than the delegates assembled on the floor.

As millions more watched the climax of the four-day Democratic National Convention (DNC) broadcast on television, Kerry was also making his case—“help is on the way”—to the undecided voters who may well determine the outcome of the Nov. 2 presidential election.

The nearly hour-long speech was in many ways familiar from stump speeches he delivered over the past year in a heated primary campaign. But in an effort to bring new life to his White House bid, Kerry also incorporated new themes—including, early in his speech, a call to arms for the cause of women’s rights—and responded in unusually blunt fashion to criticisms of his policies and style that have accumulated over the course of his run.

And after three days in which mentioning the name “Bush”—let alone openly attacking the current administration—was strongly discouraged, Kerry proved himself unafraid to address the president directly and aggressively.

While the FleetCenter’s floor was erupting in applause and campaign signs, Harvard students watching the speech from the John F. Kennedy Jr. Forum at the Institute of Politics overwhelmingly embraced Kerry’s leaner, meaner message.

“I was impressed by his tone—he didn’t sound too uptight,” Y. Edo Paz ’05 said. “He succeeded in having a truly personal demeanor.... I was impressed that he was able to pull off the most impressive speech of the convention after the great speeches of [former president Bill] Clinton on Monday and [Illinois senatorial candidate Barack] Obama on Tuesday.”

Felipe C.L. Velasquez ’05 was similarly impressed that Kerry could still hit home after four days of buildup.

“I like how he was able to come off as the flagship of the Democratic Party,” Velasquez said. “That’s not easy with so many other luminaries.”

From the first words of his 10 p.m. keynote speech—a gruff “Reporting for duty!”—Kerry emphasized what has been a defining theme of the convention and his campaign thus far. Alluding repeatedly to his now-familiar personal narrative that included service on a boat in the Mekong River during the Vietnam War—and his subsequent opposition to the unjust war that it contributed to—Kerry portrayed himself as a principled war hero wary of the dangers of armed conflict.

“I know what kids go through when they are carrying an M-16 in a dangerous place and they can’t tell friend from foe,” Kerry said. “I know what they go through when they’re out on patrol at night and they don’t know what’s coming around the next bend. I know what it’s like to write letters home telling your family that everything’s all right when you’re not sure that’s true.”

In a more fiery version of what has become one of his trademark moves, Kerry used his Vietnam experience as a platform on which to attack President Bush.

“I will be a commander in chief who will never mislead us into war,” Kerry said, going on to criticize the rest of the Bush administration in equally harsh terms, though just short of explicitly. “I will have a vice president who will not conduct secret meetings with polluters to rewrite our environmental laws. I will have a secretary of defense who will listen to the best advice of our military leaders. And I will appoint an attorney general who actually upholds the Constitution of the United States.”

And striking a chord usually reserved for those further to the left than Kerry has portrayed himself during the campaign, the senator issued a scathing critique of Bush’s energy policy and diplomacy.

“I want an America that relies on its own ingenuity and innovation—not the Saudi royal family,” he said.

Recent controversial works including Michael Moore’s Fahrenheit 9/11 and House of Bush, House of Saud by former Crimson editor Craig Unger ’71 have focused national scrutiny on the current administration’s cozy relationship with the Arab nation’s rulers, but Kerry’s more mainstream approach had previously steered clear of such territory.

Toward the end of his remarks, Kerry tempered these salvos with a remarkably direct address to President Bush that still strove to avoid a negative tone, in keeping with the convention’s general tenor of strength in cooperative unity.

“I want to address these next words directly to President George W. Bush,” he said. “In the weeks ahead, let’s be optimists, not just opponents. Let’s build unity in the American family, not angry division. Let’s honor this nation’s diversity; let’s respect one another; and let’s never misuse for political purposes the most precious document in American history, the Constitution of the United States.”

The last sentence was Kerry’s lone, particularly oblique reference to the Constitutional amendment banning same-sex marriage proposed by Congressional Republicans and supported by President Bush. But even this came as something of a surprise in a week where the issue was largely invisible in major speeches.

In describing his proposed policies on health care, labor, taxes and energy, Kerry showed an unsurprisingly populist attitude on issues involving class.

Reciting a Clintonian litany of anecdotes about ordinary Americans struggling to make ends meet, Kerry offered solutions in the form of a simple refrain echoing Wednesday’s speech by his running mate, Sen. John R. Edwards, D-N.C.

“America can do better,” Kerry said over and over again. “And help is on the way.”

“We can do better and we will,” Kerry said at another point. “We’re the optimists.”

But when it came to his own life, the Yale-educated candidate was up-front about his privileged background—mentioning that he grew up in a two-parent home, never having faced the economic challenges he vowed to address.

“The story of people struggling for health care is the story of so many Americans,” Kerry said. “But you know what, it’s not the story of senators and members of Congress. Because we give ourselves great health care and you get the bill. Well, I’m here to say, your family’s health care is just as important as any politician’s in Washington D.C.”

The frank comparison of classes, recalling both the senator’s own past rhetoric on the campaign trail and former president Bill Clinton’s sharper digs at the Bush tax cuts on Monday night, countered criticism of Kerry as an aristocratic New England liberal.

Kerry also met head-on Republican claims that his views on important issues have been inconsistent, suggesting that his evolving positions reflect an intellectual, detail-conscious approach.

“Now I know there are those who criticize me for seeing complexities—and I do—because some issues just aren’t all that simple,” Kerry said before turning those criticisms around on his opponent, who he implied has neglected the truth to stay on-message. “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. And proclaiming, ‘Mission accomplished’ certainly doesn’t make it so.”

But for all his attacks on Bush, Kerry still spent a good deal of time at the podium striving to avoid the impression of partisanship.

In one notable passage, Kerry discussed the terrorist attacks of Sept. 11, 2001 in terms of the unity they engendered among Americans rather than using them as an opportunity to bash Bush.

Calling Sept. 11 “the worst day we have ever seen,” Kerry said that it had in fact “brought out the best in all of us.”

“I am proud that, after Sept. 11, all our people rallied to President Bush’s call for unity to meet the danger,” Kerry said. “There were no Democrats. There were no Republicans. There were only Americans. How we wish it had stayed that way.”

Perhaps in anticipation of next month’s Republican National Convention, which is scheduled to occur in Manhattan just before the third anniversary of the attacks, many of the DNC’s key speakers made prominent references to Sept. 11, most falling in line with Kerry’s non-confrontational message last night.

Ending on perhaps the most uplifting note of an almost relentlessly upbeat convention week, Kerry portrayed himself as the candidate who would promote scientific and medical advances and lead America into a rosy future.

Mentioning such past American innovations as the Wright Brothers’ aeroplane prototypes, the moon-shot program of John F. Kennedy ’40, also a former Crimson editor, and microchip technology, Kerry said he would lift current administrative restrictions on embryonic stem cell research—and, in perhaps his deftest segue, tied this into the convention’s theme of an optimistic party on the brink.

“Now it’s our time to ask: What if?”

Kerry said moments before the red, white and blue balloons fell on the convention floor. “It is time to reach for the next dream. It is time to look to the next horizon. For America, the hope is there. The sun is rising. Our best days are still to come.”

—Nicholas F. Josefowitz contributed to the reporting of this story.

—Staff writer Lauren A. E. Schuker can be reached at schuker@fas.harvard.edu.

—Staff writer Simon W. Vozick-Levinson can be reached at vozick@fas.harvard.edu.