Supporters of Hillary Clinton and Bernie Sanders drowned out the opening proceedings with competing cheers and chants on Monday as discord enveloped the first day of the Democratic convention to nominate Clinton for president.
Speakers in the convention's first hour struggled to carry out business as angry Sanders supporters repeatedly booed and chanted, drawing a reaction from Clinton delegates that created a deafening roar.
"We're all Democrats and we need to act like it," U.S. Representative Marcia Fudge, the convention's chairwoman, shouted over the uproar.
Earlier in the day, Sanders drew jeers from his supporters when he urged his delegates to back the White House bid of his formal rival, Clinton.
Sanders' followers shouted: "We want Bernie" in a show of anger at both Clinton's victory in the race for the presidential nomination and emails leaked on Friday suggesting the Democratic leadership had tried to sabotage Sanders' insurgent campaign.
For months, Sanders, 74, a U.S. senator from Vermont, mounted an unexpectedly tough challenge to Clinton, 68, a former secretary of state, who this week will become the first woman nominated for president by a major U.S. political party.
Sanders complained bitterly during the primary process that the party leadership was working against him. Some of his backers are reluctant to get behind Clinton, seeing her as a member of the Washington political elite who pays lip service to their goals of reining in Wall Street and eradicating income inequality.
The scenes of booing at the convention in Philadelphia were a setback to Democratic officials' attempts to present the gathering as a smoothly run show of party unity in contrast to the volatile campaign of Republican nominee Donald Trump.
The Democratic National Committee formally offered "a deep and sincere apology to Senator Sanders, his supporters, and the entire Democratic Party for the inexcusable remarks made over email" and said it would take action to ensure it never happens again.
Democratic National Committee Chairwoman Debbie Wasserman Schultz resigned effective at the end of the convention over the email flap. At a morning gathering of Florida delegates, Sanders supporters jeered Wasserman Schultz, who they accuse of trying to sabotage the campaign of the democratic socialist.
'SHE STOLE THE ELECTION!'
Sanders, speaking later to his delegates in Philadelphia, was booed when he urged supporters to help defeat Trump in the Nov. 8 election by backing Clinton and her vice presidential running mate, U.S. Senator Tim Kaine of Virginia.
"Brothers and sisters, this is the real world that we live in," he said, adding: "Trump is a bully and a demagogue."
Members of the crowd screamed back: “So is Hillary.” "She stole the election!" someone else shouted.
While Sanders has endorsed Clinton, the former first lady faces the task of attracting his backers as she battles Trump. The New York businessman pulled ahead in at least one opinion poll on Monday, after lagging Clinton in most national surveys for months.
A CNN/ORC opinion poll gave Trump a 48 percent to 45 percent lead over Clinton in a two-way presidential contest.
Trump was formally nominated for president at a chaotic Republican convention in Cleveland last week.
Sanders was among those due to speak on the first evening of the Democratic convention. Other speakers included President Barack Obama's wife, Michelle Obama.
Some of the early speakers pleaded for unity among the competing supporters. Diane Russell, a Sanders delegate from Maine, said the party had to come together to beat Trump.
"Whether you support Bernie Sanders or Hillary Clinton, we're all in this together," she said.
SHOUTS OF 'SHAME'
Wasserman Schultz, a Florida congresswoman who resigned as the DNC head on Sunday, was the focus of anger from liberal Democrats over some 19,000 DNC emails that were leaked by the WikiLeaks website that showed the party establishment working to undermine Sanders.
She told Florida's Sun Sentinel newspaper she would not speak as planned at the opening of the event.
"I have decided that in the interest of making sure that we can start the Democratic convention on a high note that I am not going to gavel in the convention," Wasserman Schultz said. The meeting "needs to be all about making sure that everyone knows that Hillary Clinton would make the best president," she said.
On Monday morning, Wasserman Schultz struggled to be heard above boos as she spoke to the delegation from her home state. Some protesters held up signs that read "Bernie" and "E-MAILS" and shouted: "Shame" as she spoke.
The cache of leaked emails disclosed that DNC officials explored ways to undercut Sanders' insurgent presidential campaign, including raising questions about whether Sanders, who is Jewish, was an atheist.
Sanders supporters were already dismayed last week when Clinton passed over liberal favorites like U.S. Senator Elizabeth Warren of Massachusetts to select the more moderate Kaine as her running mate.
"They throw 'party unity' around as if we’re supposed to jump for joy when they mention her name," said Manuel Zapata, a Sanders delegate from California, referring to Clinton. "What we've been saying for months is obviously true: They had the finger on the scale of the campaign," he said.
The Clinton camp questioned whether Russians may have had a hand in the hack attack on the party's emails in an effort to help Trump, who has exchanged words of praise with Russian President Vladimir Putin. Republicans dismissed the suggestion as absurd.
The FBI said on Monday it would investigate the nature and scope of the hack.
Trump gloated at the Democrats' opening day disorder.
"Wow, the Republican Convention went so smoothly compared to the Dems total mess," he wrote on Twitter.