DENVER, Colorado (AFP) - Democrat Barack Obama Wednesday stood on the cusp of becoming the first black presidential nominee for a major US party after his ex-foe Hillary Clinton freed her delegates to vote for him.

Clinton’s move was the latest step in a carefully choreographed show of unity and reconciliation after their primary dust-up and set up a symbolic roll-call vote at the party’s showpiece nominating convention in Colorado.

“I am here today to release you,” Clinton said, drawing cries of “No” in a meeting of her delegates in downtown Denver, a day after she ordered her millions of primary voters to unite behind the party White House hopeful.

“You want to vote according to what is in your heart. I am not going to tell you what to do. You have come from different places and made a long journey,” she said, adding she had already pledged her vote to Obama early Wednesday.

The state-by-state roll-call vote, based on the delegate hauls apportioned during the marathon coast-to-coast Democratic primary contest was due to take place later in the day.

The run-down is a time-honored feature of the convention, which in days gone by was often fraught with tension and horse-trading, but is now merely a ceremonial affair.

Intense negotiations between the Clinton and Obama camps took place to ensure that the former first lady gets her due, and has her 18 million primary votes honored, while stressing an image of unity.

There were reports that the roll-call may be cut short to allow Obama to claim the nomination by acclamation.

Clinton’s primary voters are vital to Obama, as his White House race with Republican John McCain has tightened to a dead heat.

Later, former president Bill Clinton will grab the spotlight, under pressure to cast aside months of hard feelings to back Obama.

Obama’s vice presidential nominee Joseph Biden meanwhile is set to deliver his keynote speech, likely to hammer the convention’s Wednesday theme of national security, and to highlight his tragedy-scarred life story.

Act two of the Clinton melodrama at the convention will come a day after Hillary Clinton stirred a rapturous reception and ordered her army of supporters to back the party ticket.

Bill Clinton has been waging an ill-tempered feud with the Obama campaign for months, and has yet to offer a robust endorsement of the new party standard bearer.

Clinton, who accused the Obama camp of playing the “race card” on him, seems to have taken his wife’s loss hard, and appears to believe his legacy as the only Democrat to win two terms since World War II is getting insufficient respect.

“President Clinton will lay out the choices that we face on foreign policy,” said Obama foreign policy advisor Susan Rice.

“He will talk about how Barack Obama has what it takes to be a strong commander-in-chief.”

Reports quoting unnamed Clinton aides have said the former president will not attend Obama’s acceptance speech, due to be delivered before more than 70,000 supporters in an open-air football stadium here on Thursday night.

Meanwhile, McCain’s camp Wednesday accused Obama of only seeing Iran as a “tiny” threat in a new campaign ad, arguing he is dangerously unprepared to be president.

“Obama says Iran is a ‘tiny’ country, ‘doesn’t pose a serious threat’,” said the narrator as pictures of Iranian President Mahmoud Ahmadinejad and the Israeli flag flashed across the screen.

“Terrorism, destroying Israel, those aren’t ’serious threats’?”

“Obama — dangerously unprepared to be president.”

The Obama camp charged McCain with distorting the Democrats’ positions and using “tired” Republican strategies of playing politics with grave national security questions.

“While Barack Obama recognizes that Iran has been the biggest beneficiary of the war in Iraq and that the Bush-McCain fear of tough diplomacy has allowed Iran to spin 3800 centrifuges, threaten Israel, and fund terrorism, John McCain promises more of the same,” said Obama spokesman Hari Sevugan.

“If John McCain was serious about dealing with the threat from Iran, he would join Barack Obama’s bipartisan effort in the Senate to step up sanctions on Iran instead of adopting the same tired, old Bush-Rove playbook.”

The advertisement is based on out-of-context quotes from remarks on foreign policy by Obama in May, in which he said Iran, Cuba and Venezuela were “tiny” countries compared to the Soviet Union.

Courtesy of:http://ca.news.yahoo.com/s/afp/080827/usa/us_vote