By Jessica Yellin

WASHINGTON (CNN) -- Single women voters could be a huge force for the Democrats in the general election, but only if the Democrats can turn out the vote.

A new poll, conducted by Greenberg Quinlan Rosner and "Women's Voices. Women Vote Action Fund," shows that single women could be for the Democrats what evangelical voters were for the Republicans in the last presidential election.

Unmarried women voters make up more than a quarter of the electorate, and they tend to be Democrats, according to the poll, released Monday.

Single women surveyed preferred a Democratic president 66-29 percent.

In 2004, Democratic presidential hopeful John Kerry got 62 percent of the single women's vote, but just 44 percent of the married women's vote.

But single women are less likely to vote than married women, according to the poll, and the Democratic candidates could be at risk of losing them.

"They've gotten more excited about the election, you know, more engaged, but they don't see their issues being addressed," said Stan Greenberg, chairman and CEO of Greenberg Quinlan Rosner. "They are looking for pay equity to be addressed. Minimum wage, daycare, education, those are not issues that they've heard the candidates talk about."

There are sporadic efforts to woo women voters in general but few that target single women.

Sen. Hillary Clinton has a television ad in which she reaches out to the female voter.

"You pour coffee, fix hair, you work the night shift at the local hospital," says the announcer in the 30-second spot over footage of workers on the job.

"You're often overworked, underpaid and sometimes overlooked. But not by everyone."

Clinton and Sen. Barack Obama have policy proposals on family medical leave, day care and education. Clinton has a women's outreach office, and both candidates have addressed pay equity on the stump.

At a town hall event in Harrisburg, Pennsylvania, Obama said when "a woman's doing something that the man's doing -- a woman has to be treated fairly and get paid the same."

On the Republican side, Sen. John McCain has also reached out to women voters. He recently appeared on ABC's "The View," a show targeted at women.

A recent Pew survey from March 19-22 showed McCain's support among women lagging far behind his Democratic rivals. According to Pew, Obama leads McCain among women, 53 percent to 40 percent. Clinton, meanwhile, leads McCain among women, 56 percent to 39 percent.

That gap is something McCain needs to tackle, said Carly Fiorina, a McCain adviser and former Hewlett-Packard CEO.

"We need to acknowledge that it exists, and we need to be up front in saying we want to narrow that gap, we are going after the woman vote and he needs to be communicating aggressively both directly and through his surrogates with women all over this country," she said last week.

Monday's findings are based on a survey of 1,007 adult women, including 512 who are married and and 484 who are single. The survey was conducted from March 18-26 and has a sampling error of plus or minus 3 percentage points.

"Women's Voices. Women Vote Action Fund" is a progressive group that works to mobilize unmarried female voters.