US elections: Disunity prevails as Democratic convention gets underway

The Democratic convention opened to chaotic scenes on Monday, as rival supporters of Hillary Clinton and Bernie Sanders traded boos, jeers and taunts in a very public show of party disunity.

As Democrats gathered in Philadelphia to make Clinton the first woman presidential nominee from a major party, diehard supporters of Sanders repeatedly booed each time her name was mentioned.

Twice Sanders appealed to supporters to help build party unity, ahead of a pivotal prime-time address to delegates.

"We have got to defeat Donald Trump. We have got to elect Hillary Clinton and [running mate] Tim Kaine," Sanders told a gathering of his supporters.

"Trump is a bully and a demagogue," he said. His call to support Clinton was nevertheless met with loud jeers.

He later sent a text message to supporters asking them not to protest on the floor of the convention as a "personal courtesy" to him.

But that appeared to have minimal impact.

The party is reeling from leaked Democratic National Committee emails which show nominally neutral party staff trying to undermine Sanders' insurgent campaign and questioning his Jewish faith.

	Sanders has backed Clinton [Getty]

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 FBI said it was investigating the "cyber intrusion," which the Clinton campaign blamed on Russian hackers bent on helping Trump.

Sanders, a leftist who promised a "political revolution," lost to Clinton in the primary handily.

But the scandal has angered his already embittered supporters, who believe the deck was stacked against them.

It has led to the ousting of party chair Debbie Wasserman Schultz and an apology from party leaders.

First lady Michelle Obama stepped into the presidential election with a forceful, impassioned defence of Clinton, casting her as the only candidate who can be trusted as a role model for the nation's children.

"This election and every election is about who will have the power to shape our children for the next four or eight years of their lives," Obama said.

"There is only one person I trust with that responsibility, only one person I believe is truly qualified to be president of the United States, and that is Hillary Clinton."

New polls have showed that Trump is surging since his confirmation last week as the Republican presidential nominee, with a CNN poll putting him three percentage points ahead of Clinton - a six-point post-convention bump.

Agencies contributed to this report.