US election 2012: Michelle Obama kicks off charm offensive

On a more sombre note likely to be sounded throughout the campaign season, Mrs Obama spoke about her working class roots on Chicago's South Side and her father, who worked at a municipal water plant.

"My father had multiple sclerosis and I never knew him to be able to walk. But my dad worked so hard. And he loved us so much," she said.

"We had rules. We had boundaries, but there wasn't anything my dad wouldn't do for us. And – Don't make me cry ... This isn't Oprah," she added, earning a hearty laugh from the crowd.

President Barack Obama's campaign likely hopes that the First Lady's working class background – neither of her parents went to college – will help him to connect with Americans struggling through a slow economic recovery.

November's general election will likely turn on whether voters believe Mr Obama has turned around the US economy and deserves a second term or that one of his Republican rivals would be better able to get Americans back to work.

Source: AFP