LAKEWOOD, Colo. - They've decided big-ticket elections before, and the women of Colorado, once considered a surefire vote for President Obama, appear less certain now and may determine whether the Centennial State will help the president win re-election.

"It could go a long ways to determining who will win the state," said Michael Berry, a University of Colorado-Denver political scientist. "It's so precarious right now, and a small number of votes from one particular voting bloc could sway everything."

Obama won Colorado by 9 percentage points four years ago, in no small part because of sweeping support from women. Exit polls showed that Obama won 56 percent of the vote among women, an 8 percent jump from Democratic nominee John Kerry's performance in 2004.

Vicki Cowart, the president of Planned Parenthood Votes Colorado, said women in the state, like others around the nation, are focusing on reproductive rights, an issue Obama has emphasized throughout the campaign.

"What we're seeing across the electorate is that people really believe politicians need to stay out of this part of their business, and it does turn people out," Cowart said.

Polls show that Obama still enjoys backing from a majority of women, but that support is softening. Recent statewide polls show the broader Colorado race to be tight, allowing both candidates to claim possession of the lead in the campaign's final days.

Obama aides said they remain confident of the president's standing among the 1.87 million women registered to vote in Colorado.

"Women's strong support for President Obama is going to decide this election," Jeremy Bird, the campaign's national field director wrote in a memo that noted "hundreds of Colorado women" participated in Obama-sponsored early voting events.

The 2012 presidential contest would not be the first one that women decided. Fewer than 30,000 votes decided the state's 2010 U.S. Senate seat, with women choosing Democrat Michael Bennet over Ken Buck by a margin of 17 percent.

Buck drew the ire of women's groups -- and ultimately lost votes -- for what was perceived to be a pattern of insensitive remarks about gender.

While Romney has largely avoided gaffes on women's issues, he has drawn fire for what critics say are shifting views on issues like abortion.

"He's switched back and forth so many times that I think it's impossible to tell what he really believes, and it's very dangerous to assume one way or the other," Cowart said.

Republicans are betting that Colorado women will base their choice on the state's economy, which has an unemployment rate 1.6 percent higher than when Obama took office.

"The social issues are very important to women, but I think right now those kind of fall second to jobs and the economy," said Frances Owens, a former Colorado first lady who is helping to lead Romney's efforts to win over women. "The social issues matter, but they're not going to matter as much."

Cowart disagreed.

"I think that's another example of the folks who have these more conservative views just misreading what's going on," she said. "Women's health is an economic issue. ... When people say these are just social issues, it demonstrates they totally don't get it."