Hillary Clinton faces the test of a lifetime Thursday as she accepts the Democratic White House nomination in a defining speech aimed at prying voters away from Donald Trump -- and convincing America to entrust her with the world's biggest job.

It is the center-stage opportunity she came so close to seizing eight years ago during her first White House campaign, only to be defeated in her party's primary race by Barack Obama.

Clinton made history this week as the first female presidential nominee of a major US party. Now, she needs to hit a home run in Philadelphia, a day after Obama upped the ante with a stirring address hailing Clinton as his political heir.

For days, the most powerful voices on the American left have lined up to convince voters that the former secretary of state and one-time first lady is uniquely qualified for the Oval Office.

But Clinton faces a major trust deficit among a US public that has followed every Clintonian turn of the past quarter century. Rocked by an email scandal that refuses to die, she is now about as unpopular with voters as her Republican rival.

And while Trump casts himself as an outsider, a political neophyte committed to upending the Washington establishment, Clinton faces the difficult task of appearing as the steady hand at the tiller even while promising to be a catalyst for change.

"It's the most personal moment on the campaign, talking to a big audience about what she wants to do for the future," Clinton campaign chairman John Podesta said on a Facebook live stream.

- Demagogue -

Clinton, 68, enjoyed a stream of unrestrained praise Wednesday at the Democratic National Convention, from her running mate Tim Kaine to Vice President Joe Biden to the independent former New York mayor Michael Bloomberg.

Her chief rival in a bruising primary battle, Senator Bernie Sanders, has urged his supporters to back Clinton and draw a line under the disruptive protests during the convention's opening days that served to highlight party infighting.

But the most rousing Clinton sales pitch came from Obama himself.

"I can say with confidence there has never been a man or a woman -- not me, not Bill (Clinton), nobody -- more qualified than Hillary Clinton to serve as president of the United States of America," Obama thundered before a cheering crowd.

"No matter how daunting the odds, no matter how much people try to knock her down, she never, ever quits."

Even Trump did his part, albeit inadvertently, with his urging of Russia to hack Clinton's emails landing like an unexpected gift in her lap.

The 70-year-old real estate mogul sought to douse the outcry on Thursday by saying he was "being sarcastic," but the call for cyber espionage against the United States made even Republicans cringe.

He also stirred the pot with new controversial comments about Vladimir Putin, saying the Russian president is "certainly doing a better job than Obama is."

Clinton's backers unleashed a litany of criticism of Trump at Wednesday's convention session, with Kaine blasting him as "a slick-talking, empty-promising, self-promoting, one-man wrecking crew" and Obama calling him a demagogue.

- Pitch to middle America -

On Thursday, Clinton will have to make the case herself.

While she must play to the party's base -- and seek to soothe bruised Sanders supporters, some of whom said they will launch small-scale protests Thursday inside the arena -- a key mission is to appeal to crossover voters and independents wary of Trump.

"Donald Trump is making a lot of really big promises, and some people find those attractive," said Clinton campaign manager Robby Mook.

"What Hillary is going to do tonight, what we've done at this convention is make sure that people know the facts."

He acknowledged that Clinton, who will be introduced by daughter Chelsea, also knows "she needs to earn the voters' trust."

Clinton has never been as telegenic and personable a politician as her husband or Obama, whose oratorical skills were on full display Tuesday and Wednesday.

She will balance her policy strengths with an attempt to connect with Americans watching from their living rooms as she faces a nation divided by intense campaign rhetoric, spikes in race-related gun violence, and heightened fear brought about by a spate of terror attacks around the world.

The night will have its share of glitz, too, with musical performances by Katy Perry, Sheila E and Carole King.

Clinton will seek to carry her momentum straight onto the campaign trail Friday, when she and Kaine launch a three-day Rust Belt bus tour through parts of swing states Pennsylvania and Ohio to make their pitch to voters.

"We do know that there's a slice, however narrow, of those persuadable voters that are still making up their minds," Clinton spokesman Brian Fallon said.

Source: AFP