The Democratic Congressional Campaign Committee is building a national computer model to predict voters’ marital status, with hopes of targeting what may be the party’s most important demographic group: unmarried women.

“The completed model will let us pinpoint unmarried women as the target of specific, poll-tested messages delivered through field, mail and paid communications,” said a Democratic official who spoke on the condition of anonymity to discuss internal strategy. “The model can also be included in our polling, allowing us to monitor trends in support and enthusiasm over time.”

The DCCC project — which has not previously been disclosed — is just one example of the party’s growing focus on single female voters, who lean heavily in favor of Democrats and could spell the difference between making gains in the House and losing control of the Senate in November. President Obama and congressional Democrats are pushing a long list of issues that have an outsize effect on this particular subset of voters, including the minimum wage, pay equity and health care.

Raising the minimum wage to $10.10 an hour, for example, would benefit unmarried women more than any other demographic group, economic data show. The wage proposal was the focus of an Obama appearance in Michigan on Wednesday afternoon and is expected to receive a vote in the Senate later this week.

The aim of these and other Democratic efforts is to replicate, and build on, the campaign experience of Virginia Gov. Terry McAuliffe (D), who won election last year in large part because of a big edge among unmarried women (67 percent to 25 percent).

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“Unmarried women are a critical opportunity for us, and we learned from Terry McAuliffe’s race in Virginia just how important a factor they are,” said Rep. Steve Israel (D-N.Y.), chairman of the DCCC. But he added, “It’s an opportunity that you cannot take for granted, and that is why we are building our earliest and most aggressive field and targeting program ever.”

But Democrats have their work cut out for them. Not only do unmarried women tend to vote in far smaller numbers during midterm elections, Democrats are lagging in support from that group of voters compared with 2012.

Recent polling by Democratic firm Greenberg Quinlan Rosner showed that just under 60 percent of single women likely to vote in 2014 are backing Democrats. Generally, it is a bad sign for Democrats if they are getting less than two-thirds support among this group, said Erica Seifert, a senior associate at the firm.

“The biggest turnout factor for unmarried women is whether they feel the candidates are speaking to the issues that really matter to them,” Seifert said. “That’s the big thing that we’re watching in 2014, if there is a pocketbook-level economic debate that’s going to bring unmarried women out to vote.”

Republicans, meanwhile, are attempting to upend the Democratic strategy. The Republican National Committee is working with GOP activists in competitive races to target women with messages relative to their marital status.

Democrats “are going to have a hard time mobilizing women, because after five years Obama’s many promises to women are falling flat,” said RNC spokeswoman Kirsten Kukowski. “Women are fed up with the Democrats, and we’re going to use the opportunity to message to them. We have messaging and political campaigns dedicated to women.”

On Capitol Hill and in the White House, top strategists are attempting to shine attention on policies that will resonate particularly well with unmarried women. In its call for a higher minimum wage, for instance, the White House has gone out of its way to single out who stands to gain most.

“Right now women make up more than half of the workers who would benefit from increasing the minimum wage,” Vice President Biden said Saturday in the weekly White House radio address. “Folks, a low minimum wage is one of the reasons why women in America make only 77 cents on a dollar that every man makes.”

And most of those women are unmarried. According to the Bureau of Labor Statistics, 49.6 percent of people earning the minimum wage and below are unmarried women or women whose spouses are absent.

The focus on economic issues builds on work in the 2012 presidential election and in the Virginia gubernatorial race to attract single women by emphasizing issues such as access to contraception, aides said.

“All of these issues — on the social side and on the economic side — speak to sentiments broadly felt among Americans writ large but very specifically and saliently are felt among women, and especially unmarried women,” said a senior White House official, speaking on the condition of anonymity to discuss electoral strategy.

GOP pollster Whit Ayres argued that while Democrats may have an edge among unmarried women, Republicans have an edge among married women. He also said that the Democratic advantage among single women comes largely from minorities — who are more likely to support Democrats — whereas white unmarried women are more evenly divided between the parties.

“Unmarried women is a complicated demographic, and it’s important to understand the various elements of that demographic,” he said.

The Democratic focus on unmarried women extends beyond concerns about the 2014 campaign, reflecting a common view among party strategists that the Democratic coalition is evolving to include new groups, such as Asian Americans, and must deepen the party’s advantage among others, such as Hispanics and young people.

Unmarried women play a central role in this thinking because they represent one of the fastest-growing demographic groups in the country.

The pool of unmarried women eligible to vote grew from 44.8 million in 2000 to 53.1 million today, a 19 percent increase, according to the Voter Participation Center, which has advocated a focus on unmarried women. By comparison, the pool of married women grew from 52.8 million to 56.4 million, a 7 percent increase.

“In the past, you usually saw candidate brochures with the perfect family,” said Page Gardner, president of the center. “But today if you hear a candidate saying, ‘I was raised by a single mom’ or ‘I am a single mom’ or ‘I understand what it’s like to be a single mom,’ there’s a connection there.”

Pollsters and political demographers say unmarried women will remain a central advantage for Democrats — if they can capi­tal­ize on it. Ruy Teixeira, a left-leaning demographer, said that in 1988, Democrats held only a 57-to-43-percent advantage among unmarried women. That grew to 67 to 31 by 2012, he said.

“A large and widening gap in favor of the Democrats and a larger share of voters over time makes them pretty significant,” Teixeira said.

But Seifert, the Greenberg Quinlan Rosner pollster, said getting single women to turn out will remain a big challenge unless politicians continually emphasize issues responsive to their concerns.

“They’re a very different kind of demographic group. We live in an economy that privileges and increasingly requires two incomes to make ends meet,” she said. “Unmarried women aren’t part of that group. If that’s what’s required to enter the middle class, these women are left out of that.”