Newly elected Iowa Republican Senator Joni Ernst during an election night celebration on November 4, 2014 in West Des Moines, Iowa. (Photo by Jonathan Newton / The Washington Post)

Tuesday's election will bring the count of women in Congress to more than 100 for the first time, between both the House and the Senate. The number of female U.S. senators will either remain at 20, the same record high as set in the 2012 elections, or could reach 21 if Democrat Mary Landrieu wins the runoff election in Louisiana.

Meanwhile, the number of women in the U.S. House of Representatives now stands at 81, according to numbers tallied by the Center for American Women and Politics (CAWP) at Rutgers University, which tracks the number of women in elected office. Another four races involving female candidates, according to CAWP, are still too close to call — meaning the final tally could end up as high as 85 women in the House, compared with 79 in the 113th Congress.

And yet, despite this milestone, the presence of women in Congress still doesn't appear poised to grow by more than a trickle. Before the election, women held 99 seats in Congress. The post-election total stands at 101, and could at most reach 106.

All told, even if all four of those tight House races go to the female candidate, the ratio of women in the House wouldn't quite reach 20 percent. "This is still very slow growth," said Debbie Walsh, CAWP's director. "If the goal is political parity for women — for women to be represented in Congress in proportion to their population — we're still not close."

The number of new women elected, versus incumbents, is also a figure that sheds light on the rate of growth. And this year won't set any records. The high water mark was 1992, when 24 new women were elected. In 2012, there were 19; and in 2010, there were 13. The 2014 count currently stands at 11 new women, though it could reach 13 depending on two races that are too close to call.

Moreover, the shift in power in the Senate to Republicans could affect the number of women in leadership roles on committees. Before the midterms, Walsh said, "women were 30 percent of the majority party [in the Senate], so you saw women in really important and powerful leadership positions," chairing many major committees. "But there's a loss of leadership that comes in this partisan shift." Even with the election of Republicans Joni Ernst in Iowa and Shelley Moore Capito in West Virginia, there will still only be six GOP women in the Senate.

This year, 15 women were candidates for Senate seats on election night, 10 of them Democrats and five Republicans. And 160 women were candidates for House seats Tuesday — 109 of them Democrats and 51 of them Republicans, according to data from CAWP. "If it's a bad year for Democrats, its going to be a bad year for women, in terms of the number of women getting elected," Walsh said.

This was the first election since 1992, it's worth noting, in which more Republican women than Democratic women initially filed as candidates for U.S. Senate seats. Yet more Democratic women actually made it through their primaries to become nominees. That could be because.as Walsh observed, female Republican candidates tend to be more moderate than the conservative voters who traditionally turn out for the Republican primaries.

Financial backing and other resources may also be a factor. "Republican women don't have the same infrastructure that the Democratic women have," Walsh said. "There is nothing comparable on the Republican side to a group like Emily's List."

Despite this year's modest growth in the number of women elected, the 2014 midterms did produce some notable firsts for women. Iowa's Ernst can claim two of them: Not only will she be the first woman the state of Iowa has elected to either the House or the Senate, she will also be the Senate's first female combat veteran.

Mia Love, meanwhile, became the first African American Republican woman elected to Congress. Previously the mayor of Saratoga Springs, Utah, Love won the state's fourth district. And Elise Stefanik, a Republican who picked up an open seat in New York, became the youngest woman ever elected to Congress, at just 30 years old.

It was also a year when some of the most high-profile, competitive races involved a female candidate. Tight, closely watched Senate races in Iowa, Georgia, North Carolina, New Hampshire, Louisiana and Kentucky all featured women. All too often in the past, Walsh said, "women end up being sacrificial lamb candidates" where they don't stand a chance. That wasn't the case this year. "These were the races that could determine the balance of power in the U.S. Senate. It was important that women were candidates in those races."

There was one other interesting first this year — for a man. Republican Scott Brown, in losing to Jeanne Shaheen in New Hampshire, became the first man to lose to two different women in U.S. Senate history. He also lost to Elizabeth Warren in Massachusetts in 2012.

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