DENVER - Former First Lady Hillary Rodham Clinton took center stage Tuesday night at a boisterous Democratic National Convention that will give the party's presidential nomination today to rival Barack Obama.

Seizing a moment that once looked to be all hers, Clinton implored her followers to unify behind Obama, the charismatic Illinois senator who has inspired cadres of young and disaffected voters with his calls for change.

"Whether you voted for me or for Barack Obama, the time is now to unite for a single party, for a single purpose," the New York senator told a cheering crowd, lighted up with flashing cameras.

With her defeated followers chanting her name, Clinton delivered a rousing endorsement of Obama while providing the cathartic closure her supporters were seeking.

"This is a fight for the future and a fight we must win together," she said. "Barack Obama is my candidate, and he must be our president."

Introduced by her daughter, Chelsea, and given a five-minute standing ovation, Clinton also thanked her "sisterhood of traveling pantsuits" who buoyed her candidacy over the past 18 months. "You never gave in, and you never gave up," said Clinton, in a peach pantsuit.

Somebody yelled, "I love you!"

In a reference to the tearful moment credited with rescuing her faltering candidacy in New Hampshire, Clinton told the packed convention hall, "You made me laugh, and yes, you made me cry."

Minnesota delegate Lynn Wilson, already hoarse, was in tears during the speech, particularly when Clinton talked about health care.

She had spoken to Clinton about her fears for her son, who has a mental disorder, and the lack of appropriate health care for him as he approached his 18th birthday. At the time, Clinton told the Rochester woman, "no matter the outcome" she'd keep fighting for him.

Holding a "Hillary" sign, Wilson said: "It is so incredible. I'm so proud of her. She's doing just what we need her to do to elect Barack Obama. She didn't need to do anything, she had nothing to gain. ... She's giving everything right now."

Clinton also took some expected shots at Republican hopeful John McCain, saying it "makes sense that George Bush and John McCain will be together next week in the Twin Cities. Because these days they're awfully hard to tell apart."

'My heart hurts'

Her speech set up today's roll call vote that will make Obama the first black major party candidate in U.S. history. Still unclear, however, is how many of her supporters will cast votes for her in tonight's balloting. Although the Obama camp sought a unanimous vote, Clinton delegates said they have been released to vote as they wish.

At stake: Only symbolism and stagecraft, as Obama's nomination is assured. In a nationally televised speech sure to be a bellwether of party unity, party officials also sought to avoid Clinton floor demonstrations.

But for Clinton partisans, particularly women, this was the highlight of the convention.

Among those still struggling to reconcile her feelings was Jackie Stevenson, 73, a Clinton campaign activist and superdelegate from Minnetonka.

"It's emotional," she said. "I've spent 55 years plus in political activity, and I've always dreamed of the day we would elect our first female president. I thought 2008 would be the year. My heart hurts."

While Stevenson donned a Hillary T-shirt and remained undecided about her vote, she said she had already ordered an Obama yard sign: "We can't do anything else."

Tammy Tesky, 32, a Clinton delegate from north Minneapolis, said Clinton was "my inspiration. Obama isn't the only one getting new people out to vote. There were people of all ages, races and backgrounds who came out for Hillary."

She said she will support Obama in the election, but she intends to vote for Clinton's nomination today. "That's why I'm here. It's a historic vote."

Hoping to capitalize on Clinton's center-stage role, McCain rolled out Clinton supporters who have switched their allegiance to the Republican.

"There's quite a few of us who couldn't support Obama and never really disliked McCain," said Trudi Martinco, a retired corporate manager from Roseville.

'I'm proud of her'

But there were few if any party turncoats among the cheering throngs in the Pepsi Center while Clinton spoke.

If it was a bittersweet moment for such die-hard Clinton fans as Tesky, it was because they wanted to honor Clinton, not turn their backs on the ticket of Obama and Sen. Joseph Biden. "It's a little different than sad," Tesky said. "I'm proud of her for getting so far."

Clinton delegates, about a third of the Minnesota delegation, said they have been summoned to a meeting today to finalize the roll call of states. By some accounts, there might be a deal between Obama and Clinton allowing some states to cast ballots in a roll call before Clinton or a surrogate calls for unanimous vote for Obama.

Either way, Russ Stanton, 58, a Clinton delegate from Edina, said he will now vote to nominate Obama. What clinched it was Clinton's decision to release her delegates. "For me that's a great relief, because I feel very torn between my loyalty to the people who elected me, and the need to have a united party."

Staff writer Bob Von Sternberg contributed to this report.