Democrats expected to show up in Philadelphia to nominate Hillary Clinton, paper over their disunity and turn their fire directly on Republican nominee Donald Trump and the foreboding picture he painted of America at the GOP convention.
Instead, they were greeted by explosive fallout from a suspected Russian hack on the Democratic National Committee that exposed emails -- published by Wikileaks -- of top officials scheming against Bernie Sanders.
The storm felled the party's leader, Debbie Wasserman Schultz, who was booed by members of her own Florida delegation Monday morning in the wake of the email disclosure and ultimately shelved plans to brave the convention hall Monday night.
They also ripped the scab off the barely healed wound
of the bitter primary feud between Clinton and Sanders. And they threatened to throw the convention itself -- suddenly rattled by Trump's polling bounce after last week's Republican convention -- deeper into disarray.
Monday night will mark the official start of the convention. Clinton's team and top Democrats will reintroduce their candidate to the American public and hope to make the case that she's the best person to succeed Barack Obama in the Oval Office.
But weekend revelations of the email hack extend beyond this week's Democratic gathering. They raise the stunning question of whether the Kremlin was trying to dictate the outcome of a US presidential election and subvert the political system itself in the city that nurtured the nation's democracy.
Democratic Party leaders reacted to another sudden twist in an unbelievable political season by leveling the sensational allegation that Russian President Vladimir Putin was trying to tip the US election toward Donald Trump.
"What the experts said when this breach initially happened at the DNC was that they believed it was Russian state actors who took these e-mails," Clinton campaign manager Robby Mook said on Monday. "What further experts are saying is that then, because they possessed those emails, that Russian state actors were feeding the email to hackers for the purpose of helping Donald Trump."
Rep. Adam Schiff, who is the top Democrat on the House intelligence committee, went much further, claiming that Trump was Russia's preferred candidate because of his warm words about Putin and the doubts he has cast on the utility of NATO.
"I wouldn't put anything past the Kremlin," Schiff said, calling Trump "a dream candidate for Moscow" and describing the Russians as "very afraid of Hillary Clinton."
"The Russians have the motive, they have the means certainly," Schiff told CNN's Wolf Blitzer, adding that they had interfered in the political affairs and elections of other countries.
"They clearly have a strong preference in the presidential race," he said.
But Donald Trump Jr., the son of the Republican nominee, rejected the Democratic line on "State of the Union" on Sunday.
"It just goes to show you their exact moral compass. I mean they'll say anything to be able to win this. This is time and time again, lie after lie," Trump Jr. told Tapper. "It's disgusting. It's so phony."
CNN's Evan Perez reported on Monday that the suspected hack of the DNC computers was part of a much wider wave of Russian cyber attacks aimed at political organizations and academic think tanks in Washington, quoting U.S. officials briefed on the investigations.
The White House and State Department, however, have been more cautious than the Clinton campaign about identifying blame for the hack of the DNC emails and note that the FBI is carrying out an investigation.
"I think we need to let the FBI do their work before we try to form any conclusions here in terms of what happened and what the motivation was behind it," State Department spokesman John Kirby told reporters Monday. "The FBI's spoken to this. We're going to respect that process."
Wikileaks began publishing emails from the DNC, which appeared to give credence to the long-term complaints of Sanders supporters that the party hierarchy was biased against him, over the weekend.
The group didn't identify the source of the emails.
The alleged Moscow connection raises questions about whether Putin believes it can dictate the course of a US election set to be decided by millions of voters in November. The Trump campaign has vociferously denied any suggestion that Russia is intervening to help Trump.
"It's just absurd ... it is crazy," Trump top aide Paul Manafort told CNN's Erin Burnett on Sunday. "The conversation we should be having is: What does Russia have from Hillary Clinton's server? That's the bigger issue, not what anybody had got from the DNC server."
Republicans, especially Trump, who had to endure plenty of Democratic sniping from the sidelines last week at the sometimes chaotic GOP convention, were meanwhile jubilant.
"Wow, the Republican Convention went so smoothly compared to the Dems total mess. But fear not, the dishonest media will find a good spinnnn!" said Trump in a tweet on Monday.
It is safe to say that none of the conversation in Philadelphia on Monday was the message that Democrats want to project.
Speakers at the podium on Monday night will include first lady Michelle Obama, grassroots Democratic heroine Sen. Elizabeth Warren and Sanders himself -- who was roundly booed on Monday when he told his own supporters that it was imperative to elect Clinton and her vice presidential pick Tim Kaine.
The Democrats hoped to send the message of an intimately choreographed convention portraying Clinton as an agent of stability, as opposed to Trump's volatile persona.
But so far, allegations of Russian hacking is doing more to set the media narrative than Clinton.