House Republicans owe some of their success in chipping away at the Democratic majority to women.

Of the nine House seats Republicans flipped in the election so far, seven were won by female candidates, a reflection of a concerted effort to elect GOP women to Congress after the election of a wave of Democratic women two years ago.

At least 15 GOP women are headed to the House, and with several races still to be called, House Republican leaders estimated they could more than double the number of women in their caucus. They figured they could add more than a dozen to the current 13.

The largest number of Republican women to serve in Congress was 25, during the 109th Congress that ended in 2007.

“This is the smashing success story of the 2020 congressional election cycle,” Rep. Elise Stefanik (R-N.Y.), who launched the Elevate PAC after the 2018 midterms to recruit more Republican women to Congress, said in an interview.

The effort was driven by the Democrats’ overwhelming success in electing women; 88 currently serve in the House, many of whom won in 2018 to propel the party to the majority.

Set to take the oath in January is a diverse GOP group from across the country. Like Stefanik, who emerged as one of President Trump’s fiercest defenders during the House impeachment of the president, these newly elected Republican women are conservatives who echo Trump on a range of issues, including building a U.S.-Mexico border wall, defending gun rights and scrapping the Affordable Care Act.

One of the GOP’s biggest wins came in Minnesota, where Michelle Fischbach, a former lieutenant governor unseated 15-term Rep. Collin C. Peterson (D), the chairman of the House Agriculture Committee.

Yvette Herrell, a member of the Cherokee Nation, defeated first-term Democrat Xochitl Torres Small in New Mexico. Cuban American journalist María Elvira Salazar bested Florida Democratic Rep. Donna Shalala, who served as President Bill Clinton’s secretary of health and human services. Stephanie Bice, who will be the first Iranian American to serve in Congress, won the only Democratic-held seat in Oklahoma’s congressional delegation, defeating Rep. Kendra Horn.

State Rep. Nancy Mace, the first woman to graduate from the Citadel, unseated Rep. Joe Cunningham (D) in South Carolina.

“It’s not just Democrat women breaking glass ceilings; we broke a huge barrier Tuesday night, Wednesday morning, when the result was called in South Carolina,” Mace, who is the first Republican woman elected to Congress from South Carolina, said in an interview. “We’re seeing it across the country.”

Betsy Fischer Martin, the executive director of the Women & Politics Institute at American University, pointed to a dedicated effort to recruit and fund more Republican female candidates that really took off after 2018, when the Republican Party’s female contingent in the House went from 23 to 13, the lowest number of GOP women in the chamber in about a quarter-century.

“It was embarrassing in a sense to a lot of Republican women that care about this,” Fischer Martin said. “When you have 35 New Democratic women getting the attention and getting sworn in to Congress and you literally only have one Republican woman amongst that group — it did serve as a wake-up call.”

Stefanik said that after the 2018 results, she thought, “This is a problem. This is not reflective of who we are, who our voters are. We can do better.”

She said the key was to ensure that the party got behind the need to invest early in candidates. Those efforts seem to have paid off as at least 12 of the women backed by E-PAC won their races.

Winning for Women Action Fund made it a priority, as did Republican Rep. Susan Brooks (R-Ind.), who surprised colleagues when she announced her retirement but who stayed on as recruitment chair for the House Republicans’ campaign arm. Brooks said it was a “top priority” of hers to bring in more women, candidates of color and military veterans.

“It’s important for Republican women to be at the table as the incredibly difficult problems facing the country — as we try to solve those problems,” Brooks said in an interview.

Republican women broke records starting early in the election cycle. There were 227 Republican women who filed to run for the House, and 94 won their primaries, according to the Rutgers University Center for American Women and Politics. Both were record numbers, said Debbie Walsh, the center’s director.

“All of these success have come because they had more candidates” she said. “It’s a pretty simple story in many ways. You can’t have more women elected if you don’t get more women running.”

Olivia Perez-Cubas, the communications director for the Winning for Women Action Fund, the first GOP super PAC dedicated to electing women, said that after 2018, “a lot of Republican women watched from the sidelines thinking, ‘Why is this happening? There is no shortage of qualified women. Why can’t they win?’ ”

The group spent nearly $3 million supporting Republican female candidates. So far, 25 women endorsed by the group have won their races, including incumbents, with multiple additional races awaiting official results.

Bice applauded the recruiting efforts by organizations bolstering GOP women.

“The Democrats have that in Emily’s List, and they have for a long time, so it’s really great that we see organizations doing the same thing for Republican women,” she said in an interview.

She said women considering a run need to know they will have resources and encouragement to back them.

“Often times women have to be asked to run. It’s not a situation where we see ourselves in those roles,” she said. She described being asked by her predecessor and friend to run for state Senate in Oklahoma. She was elected in 2014 when, according to Rutgers’s Center for American Women and Politics, the state ranked 48th in the nation for the proportion of female legislators.

“That was a reality check that we haven’t talked about the need for female representation maybe as much as we could,” Bice said. “And now it’s a matter of talking about conservative female representation because there’s such a disparity.”

During a news conference this past week, House Minority Leader Kevin McCarthy (R-Calif.) touted what he described as an expanded Republican Party.

“The Republican coalition is bigger, diverse and more energetic than ever before,” he said. “We’ll likely have an additional 14 to 19 Republican women. . . . We’ll likely be adding 6 to 9 minorities to our conference, from Florida to New Mexico to Texas to Oklahoma to California.”

But there is some way to go until the number of Republican women in the House, and the number of women in the chamber overall, is representative of the population, Walsh said. This year was an “important first step,” but Republicans need to continue similar recruitment efforts in future cycles, she said.

“The party has to step up as a whole, as an entity, and say it matters to have more women in office,” she said.

Stefanik said her group will continue its efforts, including by investing to get the new group of Republican lawmakers reelected in two years. She and Brooks emphasized that the new group’s presence in Congress could inspire future growth.

“The more women we have in elected office in the Republican Party, the easier it is to convince other Republican women to run,” Stefanik said. “So all these newly elected women are going to be not only exceptional fighters for their districts, but they will be ambassadors and role models for future Republican women candidates.”