As the 2018 midterms draw nearer, Republicans in Congress are facing serious headwinds from a relatively unpopular president, a Democratic base that is especially energized, and a growing number of retirements from incumbent members. With roughly two dozen House members retiring outright and around another dozen leaving the chamber to pursue other offices, the challenge facing Speaker Paul Ryan and House Republicans is daunting.

At the same time, there is a great deal of focus on the work that has been done recruiting female candidates to take the plunge and run for office. TIME Magazine recently devoted a cover story to the wave of women who are putting their names on the ballot this year. An analysis by Dr. Kelly Dittmar of the Rutgers Center for American Women and Politics found that in November 2017, over 350 women had announced a bid for Congress, and this was "about double the number of women House candidates at this time in 2015, and more than double in elections 2014 and 2012."

The cruel irony of this political moment where so much attention is being paid to the importance of elevating women to office is that it is entirely possible Republicans will end 2018 with fewer Republican women in the House than they started with.

There are currently 84 women members of the House of Representatives, but despite Republicans being the majority party, only about a quarter of women in Congress are Republican. Of the 22 Republican women in Congress, a half-dozen are not running for re-election to the House (though some are seeking higher office). Of the remaining 16, six are running in a race that the Cook Political Report flags as competitive, leaving only ten in relatively safe position.

Dave Wasserman, House Editor of the Cook Political Report, tells me: "Over the years, many Republican groups have made concerted efforts to recruit and field more women for Congress – and they've made progress, though at a slower pace than Democrats. This year, Republicans are squarely focused on saving their majority, and it just so happens that Republican women represent some of the most vulnerable seats. As a result, the gender gap in the House could widen in 2018."

Even if every Republican woman in the House seeking re-election holds her seat – a difficult feat in a challenging year – Republicans would still need to elect six new women to the House just to break even.

Where would those women come from? "We need women to run for office, we need to recruit women to run for office, and women need to win these competitive primaries," says former RNC Chief of Staff Mike Shields, founder of Convergence Media who has helped Republican women like Rep. Karen Handel win tough races.

Let's look at the first component, getting more women to run in the first place; the academic literature and the political professionals in the field I've spoken to agree: Women need to be asked. "Recruiting early and recruiting often are vital ingredients for closing the gender gap in political ambition. In fact, recruitment might be the only quick fix for party leaders, elected officials, and political activists to pursue," concluded a 2012 study by Jennifer Lawless and Richard Fox of American University.

In recent years, Republicans have given a nod to this finding, with organizations like the Republican State Leadership Committee launching specific female-focused candidate recruitment efforts, and with the National Republican Congressional Committee elevating a young woman, Rep. Elise Stefanik, to head up their candidate recruitment efforts.

But even growing that baseline number of women running is no guarantee that those women would make it across the finish line. Those women need to win elections, and to do so means they have to win a primary. Among the candidates identified by the NRCC as "On the Radar" for "Young Guns" status – a status suggesting they are a candidate with the potential to pick up a winnable seat – 11 of the 46 announced candidates are female. Some, like Lea Marquez Peterson, are the only announced Republican candidate and therefore will likely be on the ballot in November. But many other women on that Young Guns list are far from guaranteed to advance and are facing a challenging field of mostly male primary opponents.

In a tough year for Republicans, perhaps the more straightforward way to boost the number of women in their caucus is for women to win primaries for open, "safe" Republican seats. The House Press Gallery's grimly-titled "Casualty List" identifies over thirty seats held by House Republicans that are "open" and will be filled this year, and less than half of those seats are considered by Cook Political Report to be competitive.

Getting Republican voters to elevate Republican women within their own party primaries, including and especially in ruby-red safe GOP districts, has to be a part of the path to closing the gender gap for Republicans. Republicans understandably shy away from "identity politics" in a way Democrats do not. Where Democrats for decades have had groups that explicitly endorse and support strong female candidates in primaries, Republicans are playing catch-up.

It's likely that 2018 will be a Year of the Woman election. It's going to take more women running and winning in Republican primaries too if the GOP wants rising female representation to be a bipartisan affair.