TRUMP AHEAD

Clinton had been leading Trump in national opinion polls in recent weeks but the New York businessman got a boost from the Republican convention in Cleveland where he was formally nominated last week.

Trump had a 2-point lead over Clinton in a Reuters/Ipsos opinion poll released on Tuesday, the first time he has been ahead since early May.

Clinton, who promises to tackle income inequality and rein in Wall Street if she becomes president, is eager to portray former reality TV star Trump as too unstable to sit in the Oval Office.

The star turn in Philadelphia on Tuesday will be the traditional warm spousal endorsement - with the twist that it will be a former president making the case for his wife.

"People should really get ready for a show tonight because we're going to have President Clinton talk about the Hillary that he knows," Kristina Schake, a spokeswoman for Hillary Clinton, told CNN.

Bill Clinton, president from 1993 to 2001, draws the admiration of many in the party and left office with high approval ratings. But he carries some liabilities. Liberals, including Sanders supporters, have long been critical of some of his trademark economic policies, such as the North American Free Trade Agreement with Mexico and Canada, and Wall Street deregulation.

He has been known as one of the most powerful political orators in the country. In 2012, he made an emotional case for the re-election of President Barack Obama.

In Tuesday's prime-time address, he will be capping a day in which Democrats want to showcase Hillary Clinton's achievements on issues such as women and families, healthcare and as a former secretary of state. Speakers will include women whose children died from gun violence, some at the hands of police.

Clinton, 68, will be watching from home in Chappaqua, New York, as her husband speaks, campaign officials said.