Like ghosts at the feast, Hillary and Bill Clinton threaten to project a baleful presence at what is meant to be Barack Obama's coming-out party as the Democrats' White House champion.
This month's party convention in Denver, Colorado, will proclaim Obama the nominee for November's presidential election against Republican John McCain, two months after he vanquished the former first lady's never-say-die primary challenge.
The Obama campaign is showcasing a new generation of Democratic leaders at the August 25-28 convention, officeholders who, like the Illinois senator, came of political age in the 1990s when Bill Clinton was president.
But the convention will have one foot planted firmly in the past as Obama pays obeisance to the Clintonian legacy and to his erstwhile rival's own shot at the nomination.
On August 27, there will be a "roll-call" vote to register Clinton's count of nominating delegates for the history books. She will address the convention on August 26, and the former president will speak the night of the roll-call.
"I am convinced that honoring Senator Clinton's historic campaign in this way will help us celebrate this defining moment in our history and bring the party together in a strong, united fashion," Obama said in a joint statement.
Clinton said: "With every voice heard and the party strongly united, we will elect Senator Obama president of the United States and put our nation on the path to peace and prosperity once again."
But unless a deal is done to transfer some of Clinton's delegates to Obama, the vote will show that the new standard-bearer only earned his position through the intervention of party grandees known as "superdelegates."
And the Democratic platform that is set to be adopted at the convention is expected to include language decrying sexism in US society -- even if an Atlantic magazine expose now suggests that Clinton's loss had more to do with paralyzing infighting among her staff than with any rampant gender bias.
So intra-party wounds could still fester, especially given that diehard Clinton supporters plan to rally in Denver to proclaim "Nobama" -- unless, of course, he chooses her as his running mate.
"The challenge for Obama lies in not having this convention come to closure with a clear message of unity and enthusiasm," pollster John Zogby told AFP.
"But it's not in either Clinton's best interest to come out of this convention leaving the suggestion that she's being a spoiler," he added.
"She has to go through the motions, and make those motions very convincing."
While the New York senator has made all the right noises in support of Obama at her public events since June, the former president looks still to be smarting at his wife's agonizing loss.
And old specters from the primary battle are returning to haunt the Democrats, with the McCain campaign running an Internet ad that shows Clinton making a biting remark about Obama at the height of their fight in March.
"I know Senator McCain has a lifetime of experience he will bring to the White House. And Senator Obama has a speech he gave in 2002," she says in the ad, referring to Obama's stand against the Iraq war, which Bill Clinton once dismissed as a "fairy tale."
So it will be interesting to see how the Democrats' dethroned royal couple pledge fealty to the new king, given rumors that Bill Clinton believes Obama cannot beat McCain and that Hillary wants a new tilt at the White House.
"The Clintons are the wild card at the convention," said Michael Traugott, a political scientist at the University of Michigan.
But he added that Obama "has a reasonable plan here."
"He's trying to give credit to president Clinton and Senator Clinton for their accomplishments in the '90s and in the primaries, while turning the focus forward to the general election and the problems the US faces.
"That's pretty standard issue stuff for party conventions," Traugott said.
Obama is not the only one facing a convention challenge. McCain too must pay respects to a controversial administration, while attempting to lay its ghosts to rest and move on.