PHILADELPHIA (AFP) - US Democrats scrambled to contain damaging revelations of an insider effort to hobble Mr Bernie Sanders' presidential campaign, with the party boss abruptly announcing her resignation on the eve of the convention to officially nominate Mrs Hillary Clinton.
Ms Debbie Wasserman Schultz said she would step down at the end of the convention, a move that aimed to put an end to the scandal threatening an uneasy truce within the fractured party.
Thousands of Democratic delegates were converging on Philadelphia, the "City of Brotherly Love," to elevate Mrs Clinton as the party's nominee who will battle Republican Donald Trump in the November election.
After a hard-fought primary campaign, the party had been heading to the Democratic National Convention seeming far more unified than the Republicans, whose fissures were laid bare last week as they confirmed brash billionaire Trump as their flag-bearer.
Now the Democrats are struggling with the fallout from a scandal that threatened to mushroom into a major crisis just as the party was supposed to coalesce around its nominee.
A cache of leaked e-mails from Democratic Party leaders' accounts includes at least two messages suggesting an insider effort to wound the upstart Mr Sanders campaign that had competed with Mrs Clinton - including by seeking to present him as an atheist in deeply religious states.
Bowing to rapidly building pressure, Ms Wasserman Schultz, the Democratic National Committee's embattled chair, announced on Sunday that she was stepping down at the end of the convention.
In a statement, Ms Wasserman Schultz described Mrs Clinton as "a friend I have always believed in and know will be a great president."
Her announcement came after Mr Sanders on Sunday repeated calls for her to go, with her leadership already under fire and impartiality called into question by the leaks.
Shortly after she resigned, Mr Sanders said in a statement that Ms Wasserman Schultz "has made the right decision for the future of the Democratic Party." He called for new leadership that would "always remain impartial in the presidential nominating process, something which did not occur in the 2016 race."
Ms Wasserman Schultz said she would still open and close the convention.
Despite the political chaos swirling, Mr Sanders made clear he would not make an insurgent bid for the nomination.
"We've got to elect secretary Clinton," he told NBC's "Meet the Press."
Mr Sanders and First Lady Michelle Obama headline day one of the Democratic convention which "gavels in" at 2000 GMT (4.00am Tuesday Singapore time).
Former president Bill Clinton is the star on Tuesday, while President Barack Obama and Vice-President Joe Biden take the stage on Wednesday.
While Mr Sanders has publicly endorsed his former rival, many of his most fervent supporters are organising protests in Philadelphia, with the largest expected on the convention's opening day.
Several thousand protesters converged near Philadelphia's City Hall on Sunday, many of them Sanders backers and people supporting renewable energy and anti-fracking efforts.
They vented frustration over a "rigged" party system that they said was aimed at ensuring Mrs Clinton would become the nominee.
Many in the Sanders camp have also voiced disappointment with Mrs Clinton's choice of a centre-left running mate, Senator Tim Kaine of Virginia, and the e-mail revelations only fueled the resentment.
"The e-mails just proved what we believed to begin with," Ms Dora Bouboulis of Vermont told AFP as she marched in a demonstration.
Mr Trump pounced on the leaks as he tries to scoop up disaffected voters who feel Mr Sanders - a self-described democratic socialist initially dismissed as a fringe candidate - was denied a fair shot at the nomination.
The provocative billionaire piled on after Sunday's announcement.
"I always said that Debbie Wasserman Schultz was overrated. The Dems convention is cracking up," he taunted on Twitter.
Mrs Clinton's campaign meanwhile was pushing the notion that Russia was behind the e-mail leaks, in an effort to help Mr Trump win.
"Experts are telling us that Russian state actors broke into the DNC, took all these e-mails, and now are leaking them out through these websites," campaign manager Robby Mook told ABC.
"It's troubling that some experts are now telling us that this was done by the Russians for the purpose of helping Donald Trump."
There was a decidedly anti-Hillary sentiment among the activists flocking into Philadelphia, where police were intensifying security operations.
"Hillary is more of a warmonger than Trump!" yelled one woman as she passed out flyers.
Hundreds of the Sanders supporters gathered near City Hall chanted "Feel the Bern!" and "This is what democracy looks like!"
But others echoed Mrs Clinton's message as she seeks to become the first female commander in chief, eight years after Mr Obama made history as the nation's first black president.
"We shouldn't be fearful, we're Americans," delegate Ms Patti Norkiewicz of Florida told AFP, after Mr Trump, accepting his party's nomination in Cleveland, offered a dark vision of a nation besieged by chaos and violence.
"We should be proud, united and we're allowed to disagree," she said.
