By Steve Holland
DENVER (Reuters) - Barack Obama was set to be nominated onWednesday as the Democrats' presidential candidate, a historicfirst for a black American, and Bill and Hillary Clinton markedtheir last day in the Denver spotlight.
Hillary Clinton released her delegates at the DemocraticNational Convention, freeing them to back Obama. She spoke to acrowd of about 3,000 people, including the nearly 2,000delegates she won in the nomination fight with Obama.
"This has been a joy. We didn't make it, but boy did wehave a good time trying," she said.
The crowd roared "No" when she told them that she wasreleasing them as her delegates.
"We will leave Denver united. My goal is that we win inNovember," she said.
Delegates prepared to lay the mantle of leadership on Obamaduring afternoon events in which his name was to be placed intonomination.
Obama was arriving in Denver to prepare for his acceptancespeech on Thursday to a crowd of about 80,000 people at theDenver Broncos' pro football stadium.
Speaking at a veterans' round-table in Billings, Montana,Obama said, "We've had a great convention so far."
"We've had two powerful women speak back-to-back on eachnight, Michelle Obama and Hillary Clinton," he said.
The Clintons remained a central point of focus at thefour-day convention. Hillary Clinton, defeated by Obama in abruising primary battle, was to be given a symbolic nominationfor the candidacy in recognition of her campaign -- and in aneffort to try to encourage her supporters to fall in linebehind Obama.
And former President Bill Clinton gets the chance to pickup where Hillary Clinton left off -- provide a ringingendorsement of Obama's candidacy and criticize the Republicancandidate, John McCain.
"Barack Obama is my candidate. And he must be ourpresident," she said to roars of approval in a speech that leftno doubt of her desire to set aside grievances and seek partyunity to defeat the Republicans after eight years of PresidentGeorge W. Bush.
More so than his wife, the former president has had troublereconciling with Obama after a primary feud in which Obama, whowould be America's first black president, accused Clinton ofinjecting racial politics into the campaign.
BIDEN AS RUNNING MATE
Sen. Joe Biden of Delaware will be placed in nomination forvice president on Wednesday night, and will address theconvention in the biggest speech in his political career thathas spanned more than three decades.
"It's going to be wonderful," a smiling Biden, 65, whotwice unsuccessfully ran for the White House, told reporters.
Biden is expected to play the role of "attack dog" againstRepublican candidate John McCain, who has moved slightly aheadin some polls following weeks of Republican pounding of Obama.
Some Democrats have also ripped into Obama for pickingBiden as his running mate rather that Clinton.
Republicans, who have set up an outpost in Denver, havebeen trying to exploit any signs of Democratic division. Whileconceding that Clinton made a strong speech, they reiteratedthe main thrust of their attack on Obama: that the first-termsenator is unprepared to be president.
"It seems to be a very technical speech about being aDemocrat, supporting (Obama) as a Democrat, but she neveranswered the big question (on whether he was ready),"Republican former New York City mayor and unsuccessfulpresidential candidate Rudy Giuliani told CNN.
(Additional reporting by John Whitesides, Caren Bohan andThomas Ferraro; editing by David Wiessler)