PHILADELPHIA, United States (AFP) – 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.