Michelle Obama urges voters to give husband second term

First Lady Michelle Obama admitted on Tuesday that the change her husband Barack Obama pledged in his campaign four years ago has not fully materialized but urged voters to give him another term in the White House.

Closing the first night of the Democratic National Convention in Charlotte, North Carolina, the First Lady spoke of the values that guided her husband as president.

"Barack and I were both raised by families who didn't have much in the way of money or material possessions but who had given us something far more valuable - their unconditional love, their unflinching sacrifice, and the chance to go places they had never imagined for themselves."

She went on to say:"Barack knows the American Dream because he's lived it… and he wants everyone in this country to have that same opportunity, no matter who we are, or where we're from, or what we look like, or who we love."

The First Lady even made some subtle jibes at her husband’s Republic rival Mitt Romney. She spoke a week after Romney's wife, Ann, took a dig at Obama when promoting her husband at the Republican convention in Tampa, Florida.

"For Barack, success isn't about how much money you make, it's about the difference you make in people's lives," Michelle Obama said, in a reference to multimillionaire Romney's past as a private equity executive.

With nine weeks to go before Americans cast their ballots, a recent opinion poll suggests Obama maintains a marginal lead over his Romney.

Earlier in the evening, Former White House Chief of Staff Rahm Emanuel delivered a passionate defence of the man he had worked for in the White House.

His address was preceded by a series of Democratic governors, members of Congress and mayors speaking in support of Obama and his policies, particularly his criticized healthcare reform law.

Julian Castro, the Latino Mayor of San Antonio, Texas, delivered the keynote address before the First Lady.

The Democratic convention will see Obama and Vice-President Joe Biden formally re-nominated as the party's presidential and vice-presidential candidates on Wednesday.

Former President Bill Clinton, who presided over the 1990s economic boom during his time in the White House, is the main speaker that evening.

The three-day convention culminates with Obama’s address on Thursday when he formally accepts the Democratic nomination.