Hillary Clinton has secured the Democratic Party's US presidential nomination, coming back from a stinging 2008 defeat in her first White House run and surviving a bitter primary fight to become the first woman in US history to head the ticket of a major party.  In a symbolic show of party unity, Clinton's former rival, US Senator Bernie Sanders of Vermont, told the chairwoman from the convention floor that Clinton, 68, should be selected as the party's nominee at the dramatic climax of a state-by-state roll call at the Democratic convention in Philadelphia.  Capping nearly a quarter century in public life, Clinton will become the party's standard-bearer against Republican nominee Donald Trump in the November 8 election when she accepts the nomination on Thursday.  "If there are any little girls out there who stayed up late to watch, let me just say: I may become the first woman president, but one of you is next," Clinton told the convention via a video satellite link.  In nominating Clinton, delegate after delegate made the point that the selection of a woman was a milestone in America's 240-year-old history. US women got the right to vote in 1920 after ratification of the 19th Amendment to the Constitution.  Clinton's husband, former president Bill Clinton, portrayed her in a speech to the convention as a dynamic force for change as he made a case for her White House bid.  "Hillary is uniquely qualified to seize the opportunities and reduce the risks we face, and she is still the best darn change-maker I have ever known," he said, hitting back at Republican arguments she is a Washington insider tied to the status quo.  The Democratic nominee, who promises to tackle income inequality, tighten gun control and rein in Wall Street if she becomes president, is eager to portray Trump, a businessman and former reality TV show host, as too unstable to sit in the Oval Office.  Trump, 70, who has never held elective office, got a boost in opinion polls from his nomination at the Republican convention last week. He had a two-point lead over Clinton in a Reuters/Ipsos opinion poll released on Tuesday, the first time he has been ahead since early May.  Sanders has endorsed Clinton, but some of his supporters protested in Philadelphia against the party leadership's apparent backing of her during the Democratic primary fight.  Sections of the convention hall were left conspicuously unpopulated as delegates from strongly pro-Sanders delegations, including California, walked out after Sanders moved that Clinton be named the nominee.  In 2008, Clinton was the early favourite in the Democratic race but lost a hard-fought nomination battle to first-term US senator Barack Obama, who went on to become America's first black president.  Bill Clinton's speech on Tuesday night offered an unusual twist to the warm spousal endorsement of a presidential candidate traditionally given at party conventions by a wife, not a man - let alone a former president.  Clinton put forth an alternative narrative to the Republican portrayal of his wife as a power-hungry politician who bends the rules and lacks transparency in her political dealings.  Polls show many Americans distrust Hillary Clinton.  Controversy over her use of a private email server for official business while she served as America's top diplomat dogged her during the primary election season.  She came under relentless attack at the Republican convention in Cleveland, as speakers assailed her over the email controversy and her record as secretary of state, and painted her as out of touch with ordinary Americans. Delegates weighed in with repeated chants of "Lock her up".  President from 1993 to 2001, Bill Clinton, 69, left office with high approval ratings and is known as one of the most powerful political orators in the country.  Trump appeared to approve of Bill Clinton's appearance. "Smart move by the Democrats to have Pres. @billclinton play a key role in their convention," he wrote on Twitter.
Former US president Bill Clinton will speak in support of his wife Hillary at the Democratic National Convention as he looks to rally fellow democrats.