Philadelphia (AFP) - Democratic power players Michelle Obama and Bernie Sanders offered contrasting heartfelt and hard-headed endorsements of Hillary Clinton, imploring a riven and feisty party convention to unite against Donald Trump.
As polls showed Trump ahead of Clinton in the race to the White House, the first lady wowed the Philadelphia crowd as she impeached Trump's character and hailed the inspirational power of putting a female US president in the White House for the first time.
From Sanders, Clinton's vanquished primary rival, there was a much more pragmatic embrace.
"Based on her ideas and her leadership" Clinton was a better choice than Trump and "must become the next president of the United States," he said.
The opening throes of the four-day convention in Philadelphia were dominated by boos and jeers from disgruntled Sanders supporters almost every time Clinton's name was mentioned.
Sanders had called on his backers to get behind the Democratic nominee twice on Monday before his primetime endorsement speech.
That included a text message sent to supporters asking them not to protest on the floor of the convention as a "personal courtesy" to him.
But Sanders' self-styled "political revolution" appeared to have transformed into an open revolt.
With some delegates in tears, Sanders received cheers and boos when he told the crowd: "Hillary Clinton will make an outstanding president and I am proud to stand with her tonight."
"Clinton can't beat Trump. Period," said Michigan delegate Melissa Arab, a Sanders supporter.
"A ham sandwich could beat Trump and she's not going to beat him. If she's nominated, people are going to end up with somebody bad for president."
Hoping to poach some of Sanders' supporters, Trump tweeted: "Bernie Sanders totally sold out to Crooked Hillary Clinton. All of that work, energy and money, and nothing to show for it! Waste of time."
- First family first -
Michelle Obama's message was at once conciliatory, raw and personal -- and earned by far the most positive response of the night.
"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," said the wife of America's first black president, her voice cracking with emotion.
The outgoing first lady reminisced about her two "bubbly little girls" Sasha and Malia as they entered the White House almost eight years ago, and how they are leaving it as "poised young women."
But -- in a thinly veiled jab at Trump -- she also painted a picture of a family that along the way struggled with the shrill tone of today's zero-sum politics.
"We urge them to ignore those who question their father's citizenship or faith," she said, a clear reference to Trump's baseless claim that Barack Obama is not American.
Obama will address the convention on Wednesday.
"We insist that the hateful language they hear from public figures on TV does not represent the true spirit of this country," the first lady said in a message that Democrats will hope resonates with fathers and mothers voting in November.
"Our motto is, 'when they go low, we go high.'"
Michelle Obama did not always have easy relations with Team Clinton when her husband emerged victorious during the 2008 primary race.
But she pointedly lauded the former first lady for not getting angry when she lost to Barack Obama that year.
"Hillary did not pack up and go home. Because as a true public servant, Hillary knows that this is so much bigger than her own desires and disappointments," she said.
On Tuesday it will be up to Clinton's husband, former president Bill Clinton, to address the convention and heal ideological and emotional rifts.
- Party infighting -
The party is reeling from leaked Democratic National Committee emails which show nominally neutral party staff trying to undermine Sanders' campaign and questioning his Jewish faith.
WikiLeaks at the weekend released nearly 20,000 emails from between January 2015 and May 2016, gleaned by hackers who apparently raided the accounts of seven DNC leaders.
The Federal Bureau of Investigation said it was investigating the "cyber intrusion," which the Clinton campaign blamed on Russian hackers it said are bent on helping Trump.
Sanders lost to Clinton in the primary handily. But the scandal has angered his already embittered supporters, who believe the deck was stacked against them.
It has led to the resignation of party chair Debbie Wasserman Schultz and a "deep and sincere" apology from party leaders.
Some delegates appeared willing to form a united front.
"The stakes are too high. In the end it's going to be either Hillary Clinton or Donald Trump and it's not even a close call," said Paul Czisny, a 57-year-old delegate from Wisconsin who had supported Sanders.
New polls showed Trump surging since his confirmation last week as the Republican presidential nominee, with a CNN poll putting him three percentage points ahead of Clinton -- a six-point post-convention bump.