CHARLOTTE, North Carolina (AP):

Bill Clinton, the popular former president who oversaw America's 1990s boom days, was scheduled to nominate Barack Obama for a second White House term last night, an unusual move by a Democratic Party determined to lift the spirits of voters who have lived through the worst downturn since the Great Depression.

Obama's challenger, businessman-turned-politician Mitt Romney, is seen by voters as better qualified to manage the country's still-struggling economic recovery. Clinton has been assigned to change that.

Polls find Americans evenly split in what looks to be the closest US presidential election in recent memory. While the multimillionaire Romney has an edge on economic issues, Obama is seen as better able to relate to the needs of ordinary Americans.

Indoor acceptance speech

The president arrived in the Democratic National Convention city yesterday afternoon as he decided not to deliver his acceptance speech tonight at a 74,000-seat outdoor arena, citing bad weather. Instead, he'll accept the nomination indoors at the convention site, which holds 15,000.

The shift ensured there would be no repeat of the extraordinary scene from 2008 when Obama accepted the Democratic nomination in a packed 84,000-seat stadium.

Republicans asked whether the venue change was for other reasons. "Problems filling the seats?" Republican spokeswoman Kirsten Kukowski said in a statement.

Star power

The president and his two daughters watched from the White House on Tuesday night as First Lady Michelle Obama ended the convention's opening night with star power and a deeply personal, yet unmistakably political testimonial.

"I have seen first-hand that being president doesn't change who you are, it reveals who you are," she said to huge cheers.

The first lady took the stage as the most popular figure in this year's presidential campaign. Michelle Obama earns higher favourability ratings than her husband or Romney, according to the latest Associated Press-GfK poll. And views of her tilt favourably among independents and women, two focal points in her husband's campaign for re-election.

She declared that after nearly four years as president, her husband is still the man who drove a rusty car on their early dates, rescued a coffee table from the trash and knows the struggles of everyday Americans because he lived them.

Romney was formally nominated at the Republican convention last week. His name appeared nowhere in Mrs Obama's remarks, but there was no mistaking the contrast she was drawing. She declared that "how hard you work matters more than how much you make, that helping others means more than just getting ahead yourself".