The Democratic National Convention got off to a nightmare start for Mrs Hillary Clinton, as delegates upset with the treatment of Senator Bernie Sanders filled the first day with just the sort of yelling, bickering and heckling the party had tried so hard to avoid.
In the process, it made clear that the Democratic Party is no more immune to divisions than its Republican rivals and served as a reminder that winning in November will not be easy for either candidate.
In fact, for much of the first day, there were fears the heckling would be worse than it was for the Republicans a week ago.
From the start, supporters of Mr Sanders made their unhappiness felt, booing nearly every mention of Mrs Clinton's name.
The heckling interrupted a prayer, a speech by the chairman of the proceedings, Congresswoman Marcia Fudge, and even a speech by Congressman Elijah Cummings, one of the most prominent African Americans in Congress.
While most appeared focused on the party leaders' bias against Mr Sanders that was revealed in a trove of leaked e-mails, there were protests over policy differences as well.
"No TPP! No TPP!" chants - against the Trans-Pacific Partnership free trade deal - drowned out much of Mr Cummings' speech.
Ms Fudge became so agitated with the commotion that she veered off her prepared script to urge respect. "I am going to be respectful of you and I want you to be respectful of me," she said.
She was not the only one who called for the booing to stop. Senator Sanders sent a text asking his supporters to be respectful and comedian Sarah Silverman - a die-hard Sanders fan - triggered a loud roar from Clinton fans when she said: "To the Bernie-or-bust people, you're being ridiculous."
For much of the day, aides of Mrs Clinton and party leaders met to strategise a way to tamp down the unrest. The Democratic National Committee issued an apology to Mr Sanders and embattled outgoing chairman Debbie Wasserman Schultz cancelled plans to appear on stage following the e-mail leak.
Speeches by Mr Sanders and a favourite of his supporters, Senator Elizabeth Warren, failed to completely silence the boos. But the intensity started to fade by the time the two took to the podium.
Mr Sanders used his prime-time slot to deliver a full-throated endorsement of his former rival.
"Any objective observer will conclude that - based on her ideas and her leadership - Hillary Clinton must become the next President of the United States. The choice is not even close," he said. "Hillary Clinton will make an outstanding president and I am proud to stand with her here tonight," he added.
There were moments of unity when speakers took to attacking Republican nominee Donald Trump.
Senator Warren reprised her role as the Democrats' attack dog with a speech focused on the tycoon.
She said: "What kind of a man roots for the economic crash that cost millions of people their jobs? Their homes? Their life savings? What kind of a man cheats students, cheats investors, cheats workers? I'll tell you what kind of man. A man who must never be President of the United States."
The organisers cleverly used clips of Mr Trump's most controversial comments about minorities and disabled people, interspersing the videos with speakers that personified the groups being insulted.
There was Karla Ortiz, an 11-year-old whose parents are illegal immigrants; Ms Anastasia Somoza, a disability rights advocate who suffers from cerebral palsy; and Ms Cheryl Lankford, a single mother who said she lost her savings to a Trump University scam.
The highlight of the night though was a stirring speech by First Lady Michelle Obama. She gave her first endorsement of Mrs Clinton in an address that helped to lift some of the tension.
"Today, I wake up every morning in a house that was built by slaves. And I watch my daughters - two beautiful intelligent black young women - playing with their dogs on the White House lawn," she said, noting how far the country has come.
"And because of Hillary Clinton, my daughters and all of our sons and daughters now take for granted that a woman can be president of the United States."
She added: "Don't let anyone ever tell you that this country is not great. That somehow we need to make it great again. Because this right now is the greatest country on Earth."
