DENVER — Sen. Hillary Rodham Clinton roused the Democratic National Convention last night with sharp criticism of Sen. John McCain and a full-throated endorsement of Sen. Barack Obama, her former rival for the party's nomination, urging Democrats to put the long and bitter battle behind them and unite to take back the White House in November.

"You haven't worked so hard over the last 18 months, or endured the last eight years, to suffer through more failed leadership," Clinton told an audience packed to overflowing at the Pepsi Center. "No way. No how. No McCain.

"Barack Obama is my candidate. And he must be our president."

With some Clinton supporters still voicing reluctance to back the senator from Illinois, the former first lady's address was the most highly anticipated of the convention, short of Obama's acceptance speech tomorrow night. Her appearance was designed to signal the final transition from the leader of her own historic campaign, which drew 18 million votes and pushed Obama to the limit, to unabashed supporter of the party's presumptive nominee.

Introduced as "my hero" by her daughter, Chelsea, Clinton received a thunderous welcome when she walked onstage to a sea of white placards with her familiar "Hillary" signature in blue. Before her entrance, delegates watched a video, narrated by her daughter, that not only paid tribute to her campaign but also gently mocked her well-known laugh and her inability to carry a tune.

Clinton described the passions that drove her to seek the presidency, including a desire to rebuild the economy, enact universal healthcare, end the war in Iraq and stand up for what she called "invisible" Americans. "Those are the reasons I ran for president. These are the reasons I support Barack Obama. And those are the reasons you should, too," she told an audience that included her husband, former President Bill Clinton, and Obama's running mate, Sen. Joe Biden of Delaware.

When she finished, the white placards that had greeted her gave way to narrow blue-and-white signs that said "Obama" on one side and "Unity" on the other.

TAKING AIM AT MCCAIN

Clinton called McCain "a colleague and a friend who has served his country with honor." But she told the delegates, "We don't need four more years of the last eight years," and she drew a huge cheer when she described McCain as a virtual clone of President Bush who would continue the administration's policies.

"It makes sense that George Bush and John McCain will be together next week in the Twin Cities," she said, referring to the site of the Republican National Convention in Minnesota. "Because these days, they're awfully hard to tell apart."

Obama aides said he called Clinton after watching her speech at a house in Billings, Mont., and thanked her for her support. He also called Bill Clinton and congratulated him on his wife's performance.

Before Clinton arrived at the convention, former Virginia Gov. Mark Warner, delivering the keynote address, described Obama as the candidate best equipped to put the United States on course to win "the race for the future" in an increasingly competitive global economy.

Arguing that the status quo "just won't cut it," Warner called McCain a politician who would explode the deficit, ignore the nation's infrastructure needs and continue spending $10 billion a month on the Iraq war. "That's four more years that we just can't afford," he said to cheers. "Barack Obama has a different vision and a different plan."

The election, Warner said, is not about left vs. right, but future vs. past. He said Obama would not govern as a partisan Democrat but would reach out to the opposition to get things done. "We need leaders who will appeal to us not as Republicans or Democrats but first and foremost as Americans," he said.

FIGHTING SPIRIT

If Monday night's convention program lacked a fighting spirit, Obama brought his to the campaign trail yesterday — fiercely laying out the case for his candidacy and the contrast with McCain. Obama even mentioned McCain's prisoner-of-war status in Vietnam in a way that suggested he will begin to challenge that as a credential for being president.

"John McCain has a great biography, has been a POW," Obama told a small group gathered at an aircraft maintenance facility in Kansas City, Mo. "I have a funny name." He said the Republicans are arguing "that you don't know whether I can be trusted to lead."

"But I'm just going to remind everyone here: This election is not about me," he said. "It's about you. It's about who's going to be fighting for you."

Yet even after Clinton's speech last night, McCain's campaign made it clear it would not hesitate to continue invoking her rhetoric from the primary season.

"Sen. Clinton ran her presidential campaign making clear that Barack Obama is not prepared to lead as commander in chief," McCain spokesman Tucker Bounds said. "Nowhere tonight did she alter that assessment. Nowhere tonight did she say that Barack Obama is ready to lead. Millions of Hillary Clinton supporters and millions of Americans remain concerned about whether Barack Obama is ready to be president."

SHARP SPEAKERS

In contrast to Monday's opening program, yesterday's speakers criticized McCain and Bush.

Kansas Gov. Kathleen Sebelius, in whose state Obama's mother was born, called McCain a candidate who "believes in country-club economics," who would privatize Social Security and who has supported tax breaks for companies that ship jobs overseas.

She also mocked McCain for the number of houses that he and his wife, Cindy, own. "Barack Obama has a plan to save the dream of homeownership for families who've lost their homes or fear they can never afford one — unlike John McCain, who has so many he can't keep track of them all," she said.

Rendell, whose unscripted remarks earlier yesterday may have created some heartburn for the Obama team, was fully on script when he appeared onstage in Denver, attacking McCain on energy policy.

"If you look past the speeches to his record, it's clear: John McCain has never believed in renewable energy and he won't make it part of America's future," Rendell said. "For all his talk, here's the truth: John McCain voted against establishing a national renewable-energy standard. He voted against tax incentives for renewable-energy companies. And for all his talk of drilling, he refused to endorse a bipartisan effort to expand domestic oil production because that bipartisan proposal would end tax breaks for Big Oil."

The night's speakers also included Sen. Robert P. Casey Jr. of Pennsylvania, a prominent Obama supporter during the Democratic primaries. Sixteen years ago, his father, then governor of Pennsylvania, was denied a speaking slot in part because he opposed abortion rights.

"Barack Obama and I have an honest disagreement over the issue of abortion," Casey said last night. "But the fact that I'm speaking here tonight is testament to Barack's ability to show respect for the views of people who may disagree with him."