"Politicians are in the pockets of big companies," she said. "Obama understood the problem. He wasn't going for that."

Today, Formato's enthusiasm has waned. "He hasn't changed anything," she complained. Nonetheless, she added with a shrug, "I would give him another shot."

The president's fierce struggle for re-election hinges in part on women such as Formato, whose support has turned lukewarm. The 31-year-old stay-at-home mom lives in a swing district in a swing state - the sprawling suburbs of Arapahoe County, southeast of Denver.

Few doubt that Obama will win a majority of female votes nationwide, as he did in 2008. The question is whether he will capture enough of them in key states to offset a comparative lack of enthusiasm among men. And the cracks in his support among women appear to depend on whether they have children or not.

According to a national Reuters/Ipsos poll of 25- to 45-year-olds, mothers tend to differ from women without children on issues ranging from the economy, taxes and military spending to healthcare and birth control - as well as on presidential candidates.

Childless working women favour Obama over Mitt Romney, the presumed Republican nominee, by a striking 20 points, 46% to 26%.

"Obama has done pretty well, stimulating the economy, getting out of Iraq and investing in healthcare," said Joanna Giddens, 27, who works for a Denver nonprofit and can't afford health insurance.

Working mothers were less likely to favour the president, by 42% to 34%. Stay-at-home mothers such as Formato, along with unemployed mothers, gave the president only a five-point margin: 37% to 32%.

What the groups have in common is that, so far, no more than three out of 10 of the women polled support Romney.

In 2008 women made up 53% of the electorate, and Obama won their vote by 13 points over John McCain, compared to his overall victory of seven points. Then in the 2010 congressional elections, women voted Republican by a narrow margin. They helped elect a GOP-controlled House that has sought to thwart the president's agenda.

Today, Obama and Romney are neck and neck in the polls, and both are furiously courting female votes.

"It's a scary time to be a woman," says a thirtysomething woman in an Obama ad that aired in swing states. A narrator explains: "Romney opposes requiring insurance coverage for contraception, and Romney supports overturning Roe versus Wade," the 1973 Supreme Court decision affirming the right to abortion.

Democrats are accusing Republicans of a "war on women".

Romney has responded by homing in on women's financial insecurity. "The real war on women is being waged by the Obama administration's failure on the economy," he says.

On Wednesday, Romney announced a new "Women for Mitt Coalition" headed up by his wife Ann, who is more popular than he is, according to some polls. - Reuters