Philadelphia - Hillary Clinton stood poised to win her party's presidential nomination on Tuesday with husband Bill tasked with steeling fractious Democrats for the White House fight against Republican Donald Trump.She will be formally proclaimed the party's nominee after a roll call vote at around 18:00 (22:00 GMT) at the Democratic National Convention, making the former first lady and secretary of state the first female presidential candidate of a major US party.Although the outcome is a foregone conclusion, the vote could be an occasion for rowdy displays on the convention floor by diehard Bernie Sanders frustrated with their candidate's loss to Clinton in the party's primaries.After a chaotic opening day disrupted by protests and a rancorous fight over leaked emails showing party bias against Sanders, the Vermont senator called on supporters to get behind Clinton."What we must do, or forever look back in regret, is defeat Donald Trump and elect Hillary Clinton," Sanders said on Tuesday while addressing the California delegation."In my view, it's easy - it's easy to boo, but it is harder to look your kids in the face who would be living under a Donald Trump presidency," he said.Trump, meanwhile, took the usual shots at Clinton during a speech to the Veterans of Foreign Wars in Charlotte, North Carolina, calling her "Crooked Hillary" and charging that her use of a private email account as secretary of state "put America's entire national security at risk".A Clinton campaign official said Tuesday's events aim to draw a sharp contrast with Trump with a line-up of speakers who will talk about her life-long fights to make a difference.Chief among them will be former president Clinton who takes the stage during primetime to hail his wife as a "change-maker", the official said.But Bill Clinton and the others - who include mothers who have lost children to gun violence or in clashes with police - will also have the unstated mission of mending fences with Sanders' army of vocal young activists. 'I'm with her' The convention's opening day reflected a startling amount of discord with the session disrupted by persistent boos and jeers from disgruntled Sanders supporters.Michelle Obama appeared to soothe some of the Sanders zealots on Monday night, as she delivered a heartfelt endorsement from one first lady to another and hailed the inspirational prospect of a first female US president."In this election, I'm with her," Obama said.She offered a thinly veiled jab at Trump while discussing how her family has had to adapt to the shrill tone of today's politics."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."Our motto is, 'when they go low, we go high'." The passionate delivery prompted her husband Barack Obama, who addresses the convention on Wednesday, to tweet his appreciation of her "incredible speech"."Couldn't be more proud & our country has been blessed to have her as FLOTUS," he posted on Twitter. "I love you, Michelle."From 'political revolution' to revolt Sanders called on his flock to get behind Clinton twice on Monday before his primetime endorsement speech, including by texting supporters asking them not to protest on the convention floor, as a "personal courtesy" to him.But Sanders' self-styled "political revolution" appears to have transformed into a revolt.Sanders himself was booed by some sections of the audience when he told the crowd: "Hillary Clinton will make an outstanding president and I am proud to stand with her tonight." Michigan delegate Charles Niswander, 28, said he and other Sanders delegates would never line up behind Clinton."None of them want her. The people who voted for Bernie," Niswander said.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."There is obviously more than four days' work necessary to heal all the wounds, and everybody accepts that," said Clinton delegate Josep Carlson, 64, of Massachusetts.Bill Clinton's highly anticipated address could jump-start that process.The 69-year-old Democratic icon, while no longer the charismatic speaker he once was, remains a powerful force on the national stage.He has played such a role before. At the 2012 Democratic convention, he delivered closing arguments for why Barack Obama should be re-elected, a voice of experience explaining Obama's policies in clear, cogent detail and why he felt Republican policies were failing.