Obama seeks to unite Democrats as party faithful gathers for convention

But his selection of veteran senator Joe Biden, seen as a champion of white working- class voters, highlights the unspoken fear of Democrats as Obama bids to become the first African-American president: Is the U.S. ready to put a black man in the White House?

Election analysts are united that in choosing Biden - the man who plagiarised a Neil Kinnock speech 20 years ago - Obama has plugged the gap in his foreign relations experience, while countering perceptions of elitism.

Two of a kind: Joe Biden has been named as Barack Obama's running mate

But the experts also agree Biden was brought on board to help tackle the key issue less openly admitted - that many American whites, particular poorer working- class whites, remain reluctant to see a black president.

Much of the so-called 'blue collar' vote eluded Obama during the bitter primary campaign earlier this year with his rival Hillary Clinton.

Now that she is out of the picture, there are fears among campaign chiefs that the blue collar vote in swing states, such as Pennsylvania and Indiana, could go against Obama.

They are worried that Obama's colour, and even foreign- sounding name, will have an effect on how Americans eventually vote.

A recent poll showed that at least 10 per cent of Americans believe Obama is a Muslim even though he has repeatedly said he was brought up a Christian and attended a Chicago church for over two decades.

The race issue has been described by one black civil rights activist as the 'elephant in the room'  -  a subject no one wants to talk about.

Riding a wave: Biden with his wife Jill at their home in Delaware after the news

Political analysts say it is up to Obama at the convention to persuade Americans that his colour has nothing to do with his ability to be commander-in chief.

Months of planning has gone into the four-day convention, and with blanket coverage of it on U.S. TV, campaign chiefs are determined to make every minute count.

Obama's wife Michelle will be the first keynote speaker today. She is expected to portray her husband as an example of the American dream.

Tomorrow Hillary Clinton will be centre stage. With as many as 40 per cent of those attending the convention having voted for her in the primaries, her speech is seen as crucial to Obama.

Her husband Bill, a two-term president, will also be speaking.

The convention's most crucial moment will be Obama's Thursday night acceptance
speech, on the 45th anniversary of Dr Martin Luther King Jr.'s 'I have a Dream' speech.

Although Joe Biden stole one of Neil Kinnock's most acclaimed political speeches almost word for word, the pair have become firm friends.

Mr Biden was forced to quit as a presidential candidate in 1988 after the speech scandal.

At the Welsh Labour Party conference in May 1987, Mr Kinnock said: 'Why am I the
first Kinnock in a thousand generations to be able to go to university? Was it because all our predecessors were too thick?'

Three months later Biden said: 'Why is it that Joe Biden is the first in his family ever to go to a university?

'Is it because our fathers and mothers were not bright? Is it because I'm the first Biden in a thousand generations to get a college and a graduate degree that I was smarter than the rest?'

More than two decades on, Mr Biden appears to be goodhumoured about the incident.

Lord Kinnock said that the senator introduced him to aides by saying: 'Do you know this guy? He used to be my greatest speechwriter.'