Hillary Clinton isn’t the only candidate trying to break a glass ceiling in 2016. In Colorado’s 6th Congressional District, former State Senate Minority Leader Morgan Carroll hopes to unseat GOP incumbent Rep. Mike Coffman to become the district’s first congresswoman.

In Colorado, the artificial barrier for women in top political offices is thick: Our state has never elected a woman as U.S. senator or governor, and has just one woman, Diana DeGette (D), serving in Congress. (However, Colorado does have the highest representation of female state lawmakers in the country.) “Elected government overall needs to be reflective of the communities that they want to represent,” Carroll said in a recent interview with 5280, that includes women, minorities, people with disabilities, and all disenfranchised voters.

Breaking through that glass ceiling will be challenging in CD-6: A redistricting after the 2010 census made the suburban area—which is centered in Aurora and consists of the western portions of Arapahoe and Adams counties, plus a portion of Douglas County—one of the nation’s most expensive and competitive House races.

Once a Republican stronghold (Tom Tancredo represented CD-6 for years), the district now has Hispanic, black, and Asian voters making up about a third of the electorate. Veterans are another key constituency (Buckley Air Force Base is the district’s largest employer), as are younger voters migrating from Denver to the suburbs.

But the ultimate swing votes in this battleground belong to moderate, suburban women. Overall, women make up just over half of the district’s electorate, and it’s possible that their votes will decide the winner in this hotly contested race. “Women will decide any close election,” says Debbie Brown, director of the Colorado Women’s Alliance (CWA), a right-leaning organization that researches issues of concern to unaffiliated women voters. Brown was Coffman’s campaign manager in 2010, and the organization has endorsed him in this election. “I started CWA shortly after [the 2010] election cycle in large part because I saw how important the role of women voters was in shaping elections.”

Women nationally outnumber men among registered voters, and have turned out to vote in greater numbers in every presidential race since 1980. Gender gaps in how men and women vote are another important factor. In 2012, women were 53 percent of the national electorate and President Barack Obama won female voters by a 12 percent margin.

In 2016, Democrats like Carroll are trying to capitalize on Donald Trump’s unpopularity among women to win the swing votes of unaffiliated female voters who tilt Republican, and that could be a problem for the GOP: Some 60 to 70 percent of suburban women hold negative views of Trump. And that was before the Washington Post released a 2005 tape that caught Trump bragging about sexually assaulting women. FiveThirtyEight has even created visuals showing how soundly Trump would be defeated if only women voted.

Part of Carroll’s strategy to win over women voters has always been to link Coffman to Trump on a wide range of issues, from immigration to reproductive rights. Both Trump and Coffman, for example, want to defund Planned Parenthood and support abortion restrictions.

For his part, Coffman has taken steps to distance himself from Trump. After the recent video release, he joined GOP Senator Cory Gardner and U.S. Senate nominee Darryl Glenn in calling for Trump to exit the race. Coffman, who was unavailable to be interviewed for this article, stated that he would not vote for Trump or Clinton, and may not vote for president at all. Coffman is also attempting to tie Carroll to Clinton: Both are endorsed by Planned Parenthood and NARAL Pro-Choice America.

The candidates’ strategies to woo women voters differ greatly from the 2014 race between Coffman and his Democratic challenger Andrew Romanoff. Thanks to a personhood amendment on the state ballot, which opponents argued would have made abortion and some types of birth control illegal, reproductive health dominated the election. (In the 2014 Senate race between Cory Gardner and Mark Udall, half of independent women voters said the campaign messaging focused too heavily on reproductive health, although Udall narrowly won this segment of the vote, according to a CWA survey.) In the 6th District, Romanoff criticized Coffman for his past support of personhood. But Coffman flipped his position on the controversial measure and won reelection.

In 2016, personhood is not on the ballot and so-called women’s issues have shifted to include a broader focus on economic and family issues. Two-thirds of women nationally say they’re more likely to vote for candidates who support workforce equity. And in Colorado, unaffiliated women ranked equal pay as the most important proposal for helping women, according to CWA research. “Gender pay and equality come up more this election than we have ever seen,” Brown says. “Unaffiliated women want to see what candidates have to say.”

Coffman has voted against equal pay legislation, such as the Paycheck Fairness Act and the Lilly Ledbetter Fair Pay Act, and said no to paid family leave for federal employees. His campaign declined to update these positions. According to the CWA, the organization endorsed Coffman due to his military experience, his record on national security issues, and his support for Colorado’s working families.

Rather than outlining a specific message for women voters, Coffman’s campaign instead points to legislative priorities that include co-sponsoring the Pregnant Workers Fairness Act and combatting military sexual assault. He also campaigned with presidential contender Carly Fiorina at a “working women” event in Greenwood Village in August to highlight business opportunities for women. “Mike will do well with women for the same reason as he does well with all voters—he’s independent, he’s a leader, and he does his absolute best representing the people of this state,” says spokeswoman Cinamon Watson.

Carroll’s message to women voters is focused on inclusivity and strengthening families. “We want to make sure that we are not reducing women down to one issue,” she says. “I think the bigger threat that women have always faced is about whether we have an equal say over our own lives. That means job access. That means equal pay for equal work. That means paid sick leave. That means retirement security. That means student debt.”

Colorado Democrats historically turn out in larger numbers in presidential elections, according to Jennifer Donovan, Carroll for Colorado campaign manager and former executive director of the Colorado Democratic Party. At the same time, the Secretary of State’s office says the percentage of active Republican voters in the 6th Congressional District is the lowest it’s been since the redistricting went into effect in 2012. This means that Democrats have a real chance to pick up a seat in a historically conservative district. But no matter the outcome of this year’s race, the winner shouldn’t get too comfortable. The 6th is likely to remain a swing district, and women will continue to sway the results.