Barack Obama will seek to bond with Americans still wary of his exotic life story and crusade for change, as he makes history by becoming the first black presidential nominee this week.
The 47-year-old son of a Kenyan goat herder and a white American mother will cap a stratospheric political rise by formally accepting his party's charge as millions of voters tune into the Democratic National Convention from Monday.
Amid razamattaz that only a White House race can whip up, Illinois Senator Obama will try to recast the sprint to November's election, after a barrage from his Republican foe John McCain reduced the race to a dead heat.
A compelling subplot will also unfold, as Hillary Clinton, who saw Obama halt her own quest for history and bid to become America's first woman president, is embraced by a party carved in two by their acrimonious duel. The former first lady, and her still smarting husband ex-president Bill Clinton, usurped after dominating Democratic politics for a generation, will be scrutinised for any sign they are thwarting party unity.
With millions of voters tuning into the race for the first time, Hawaii-born Obama has a priceless chance to flesh out his biography, and to portray his rags to riches story as the very embodiment of the American dream. "He has to make people more comfortable with him as a person," said Andrew Dowdle, a political science professor at the University of Arkansas.
"This is his real opportunity here." Obama preaches a post-racial message of unity and hope, but his image and bid to court core blue-collar Democrats was rocked when tirades of his African-American former pastor exploded into public view early this year.
Recent McCain attacks have also set him back, painting his soaring rhetoric as the stuff of a vacuous and hubristic celebrity woefully lacking experience required of a US commander-in-chief. Julian Zelizer, a history professor at Princeton University, agreed Obama's White House hopes may rest in defining himself, before Republican political shock troops do it for him.
"If he doesn't, he is going to have a big problem," Zelizer said. "He has had a really difficult month in August, and the Republicans have done a pretty good job in framing him." The unknown Illinois state lawmaker who took US politics by storm with a stunning speech at the 2004 Democratic convention, preached an end to slash and burn politics.
But the Obama of August 2008 seems to have embraced some of those tactics, fighting Republicans who take a scorched earth path to the White House. In 2004, doomed Democratic nominee John Kerry was doomed for going too easy at his convention on President George W. Bush.
Obama's stiffened rhetoric and pick of veteran bruiser Senator Joseph Biden as his vice presidential running mate, suggest he won't make a similar mistake. "I assume we are going to hear more contrast between what Democrats are about and what he is about versus McCain," said Zelizer. "We are going to hear a lot of connecting between McCain and Bush."
Opinion polls show overwhelming numbers of Americans are dismayed with the direction the country is headed, yet Obama, supposedly the candidate of change still cannot put his rival away. This phenomenon was conformed Sunday by a new Washington Post-ABC News poll, which showed Obama with 49 percent support among most likely to voters and McCain with 45 percent.
"If Democrats allow McCain to be the candidate of change then we are going to have a much tougher time," said Celinda Lake, a Democratic pollster. "In the last month we have allowed too much of that."
The four-day Democratic extravaganza, to be followed by the Republican National Convention in St. Paul, Minnesota next week, will take place under an intense security operation. An estimated 3,000 to 5,000 police and security personnel to be deployed in Denver to enforce law and order on its streets.
As well as Obama, Biden and the Clintons, it will feature the party's greatest heroes, including a tribute to liberal lion Senator Edward Kennedy, who is fighting brain cancer. In a spectacular coda to the event, Obama will take the event outside to give his acceptance speech before more than 70,000 supporters at Invesco Field, an American football stadium on Thursday.
The last time a presidential candidate accepted the nomination outdoors was in 1960 when John F. Kennedy spelled out the generational call for renewal that many Obama followers see replicated in their hero.