Bernie Sanders supporters erupted in boos and chants almost from the moment the Democratic convention was called to order today.
They ignored pleas from their candidate to avoid protests threatening to undo the carefully crafted display of unity that Hillary Clinton's campaign had plotted for her formal nomination.
As it became clear that the fall of the Democratic National Committee chief wouldn't be enough to quell the anger of the Vermont senator's delegates, representatives from the Clinton and Sanders campaign held an urgent meeting to come up with a plan to avoid disruptions, according to a party official.
The result was a text from Sanders, who lost the nomination to Clinton, to his delegates asking "as a personal courtesy to me not to engage in any kind of protests'' on the floor of the convention.
It had little effect.
When the Reverend Dr Cynthia Hale gave the invocation and mentioned the nomination of Clinton, the crowd erupted in a mixture of cheers and chants of "Bernie, Bernie, Bernie''. Clinton supporters responded with "Hillary'' chants to drown them out.
Another round of cheers and boos and chants ensued when Ohio Congresswoman Marcia Fudge, the convention chairwoman, talked about putting Clinton and running-mate Tim Kaine in the White House.
"Excuse me," Fudge said as the cheers and boos interrupted her for several seconds.
Fudge then asked for delegates to be respectful and said, "We are all Democrats and we need to act like it".
The fall of Democratic Party chief Debbie Wasserman Schultz so far hasn't satisfied many Sanders supporters, who long complained that the party organisation she led was biased in favour of Clinton during the primaries. Sanders felt the heat of the fire he lit among his supporters earlier. After praising the party platform his allies had negotiated as most "progressive" in the party's history, he drew boos at a rally when he said Republican Donald Trump must be defeated and the Clinton-Tim Kaine ticket elected.
"Brothers and sisters, this is the real world that we live in," Sanders said. Wasserman Schultz's planned resignation as party chairwoman at the end of the convention represented progress for "those people who want real change".
The crowd responded with chants of "We want Bernie".
The convention opened in Philadelphia with Wasserman Schultz absent from the DNC chair's usual place on the stage bringing down the gavel. Her decision to resign after the convention ends did little to quell the furore brought on by the leaking of hacked DNC emails that showed the party apparatus favouring Clinton over Sanders. She had decided not to gavel in the proceedings in order to start the convention "on a high note," she told a newspaper from her home state of Florida, where she faces a re-election fight to the US House.
That duty fell to Baltimore Mayor Stephanie Rawlings-Blake. Delegates on the first day were expected to vote to approve the party's platform and rules, and the convention, as well as a national television audience, would hear addresses from Sanders and first lady Michelle Obama.
Democrats came into Philadelphia trying to avoid the spectacle of divisions that defined the Republican convention last week. The danger might be even bigger for Democrats and their presumptive nominee. While Texas Senator Ted Cruz was booed off the stage in Cleveland for refusing to endorse the party's nominee, Trump, he doesn't have the following, in numbers or devotion, that Sanders has commanded throughout the primary campaign.
Even before she handed over the gavel, there were warning signs that Wasserman Schultz retaining a role at the convention would draw more dissent from progressive activists despite her resignation and distract from Clinton's historic moment as the first woman to be nominated for president by a major US political party.
Wasserman Schultz was jeered by protesters, some holding pro-Sanders signs, when she spoke at a breakfast hosted by the Florida delegation to the convention. She attempted to speak over the protesters about a recent shooting in the state and about Florida's importance as a battleground in the election, before she eventually left the stage.
"For the life of me, I can't figure out why the deal that was cut to get her to step down allowed her to not only stay on through the convention but allowed her to speak as well. The fact that she was booed so heavily at the Florida delegation is embarrassing and an un-needed distraction right now," said Jim Manley, a former communications adviser to Senate Minority Leader Harry Reid. "I understand that Senator Sanders will not raise a stink during his convention speech, but his supporters sure will."
The feuding wasn't lost on Republicans who had been the focus of Democrats' taunts during their own convention last week. "Hey @Reince - I'm in Cleveland if you need another chair to help keep your convention in order," said a tweet by Wasserman Schultz on July 18 to her GOP counterpart, Reince Priebus, that her critics resurfaced.
In campaign stops in North Carolina, Clinton didn't address the furore in Philadelphia, focusing instead on attacking Trump for what she described as his go-it-alone foreign policy and bigotry.
The party made efforts to avoid public dissension at the convention over voting on its rules and platform. At a meeting of the rules committee on Sunday, Clinton supporters voted down a number of amendments proposed by Sanders supporters to eliminate or dilute the role of superdelegates.
Sanders had complained the party leaders and officials not selected by primaries and caucuses should not have the power to decide the nomination.
Eventually, the committee passed a so-called unity amendment, backed by both the Clinton and Sanders campaigns, that will establish a commission after the election to examine the entire nominating process.
Sanders' campaign also went into the party's platform committee meeting earlier this month prioritising amendments banning fracking, opposing the Trans-Pacific Partnership, and supporting a Medicare-for-all single-payer healthcare system.
During a contentious two day of meetings in Orlando, where Clinton backers held a slight majority, the committee voted down the Sanders amendments. Instead, the two campaigns passed several so-called unity amendments negotiated by Sanders and Clinton staffers on climate change, immigration, policing, and criminal justice reform in an effort to avoid a floor fight.
The platform called for raising the federal minimum wage to US$15 an hour over time, taxing some of the income of people earning more than US$250,000 to expand Social Security, and imposing a "multimillionaire surtax" to ensure the wealthy "pay their fair share".
The document also included provision aimed at Wall Street, including a "financial transactions tax on Wall Street to curb excessive speculation and high-frequency trading, which has threatened financial markets."
While Sanders lauded the platform, he told his supporters on party committees that their movement would still continue to fight to block the TPP trade deal and pass Medicare-for-all.
He called a compromise reached by the two campaigns on superdelegates "a major victory in transforming the Democratic Party".
A turning point in the turmoil may come today when Sanders, who fought Clinton to the end of the primary before endorsing her, delivers an address to delegates and a national television audience. Clinton campaign manager Robby Mook said he is "very confident" Sanders would deliver a rousing speech in support of Clinton.
Donna Brazile, a longtime Democratic strategist set to take over as interim head of the DNC, tried to appease dissenters by issuing an apology. "I apologise to not only Senator Sanders but all of the other individuals, our donors, our volunteers," Brazile said on ABC.
With Trump and his running-mate, Indiana Governor Mike Pence, holding campaign events in Virginia and North Carolina and looking to take advantage of Democrats' divisions, Mook dismissed two newly released polls that show the race between Clinton and Trump tightening with the Republican nominee getting a boost coming out of the Republican convention.
"We'll have some lift coming out of ours as well," he said.
The resignation of Wasserman Schultz following the leak of the emails has added an element of international intrigue to party tumult. Party officials have noted that Trump has taken stances that might find favour in Russia while not directly linking the email hack to Russian support for the Republican candidate.
Clinton campaign chairman John Podesta said on MSNBC that "what we have is a kind of bromance going on between Putin and Trump". He cited Trump's statements about the the relevance of the Nato alliance and his questioning of whether the US should leap to the defence of allies who haven't fulfilled commitments on defence spending.
Trump tweeted, "The new joke in town is that Russia leaked the disastrous DNC e-mails, which should never have been written (stupid), because Putin likes me."
The Federal Bureau of Investigation is investigating DNC hack, the bureau said. The Russian Government has denied involvement.
Mook was careful in addressing questions about the role of Russians hackers in the breach of DNC emails and their subsequent release. "I want to let the experts speak on this," he said, adding that analysts have concluded the hack was "perpetrated by Russian state actors." He said that "considering the calculated release," experts have inferred that "it was the Russians who perpetrated this leak for the purpose of helping Donald Trump and hurting Hillary Clinton."