If Democrats take back the Senate in 2016, they'll likely have women to thank for it.
The party is likely to have at least six female nominees who are challenging Republican incumbents in their top-targeted states, helping them flip the four seats necessary to take back Senate control, if Democrats hold the White House.
And Democrats believe they have the perfect storm brewing to help them do that — likely the first female presidential nominee coupled with a probable GOP nominee who has a well-documented history of controversial remarks about women.
"With Donald Trump's toxicity permeating the Republican Party, never has there been a better time for a slate of Democratic women who remain focused on issues rather than insults," said Marcy Stech of EMILY's List, whose group helps recruit pro-abortion rights women to run for political office.
And if women win in these top-targeted races, they're on pace to break the current record of 20 women in the Senate. If Democrats run the table, women could make up nearly a quarter of the upper chamber come January 2017.
Women headline top 2016 Senate races
In all, Democrats could have nine female Senate nominees; Republicans have two female incumbents running for re-election, New Hampshire's Kelly Ayotte and Alaska's Lisa Murkowski.
Two current female Democratic senators are retiring this year — California's Barbara Boxer and Maryland's Barbara Mikulski. Boxer is likely to be replaced by a woman (Attorney Gen. Kamala Harris leads Rep. Loretta Sanchez in polls). But they'll be down at least one after Rep. Chris Van Hollen defeated Rep. Donna Edwards in the Maryland Democratic primary last month.
One marquee general election race will be won by a woman either way — Ayotte is being challenged by Democratic Gov. Maggie Hassan.
And in many of the Democrats' top Senate targets, they already have or are likely to get women as nominees: Rep. Tammy Duckworth in Illinois, former state environmental chief Katie McGinty in Pennsylvania, former Attorney General Catherine Cortez Masto in Nevada, former state Rep. Deborah Ross in North Carolina, and Rep. Ann Kirkpatrick in Arizona.
Iowa isn't yet a top target, but could become more competitive; the national party has endorsed former Lt. Gov. Patty Judge in the Democratic primary to try to unseat GOP Sen. Chuck Grassley.
How big will the 2016 gender gap be?
Presidential years are typically good boosts for women seeking office anyway, given the more favorable dynamics for Democrats — more female voters turning out, more minorities and younger voters. Democrats have had more success at recruiting women to run overall too, given the typical demographics of their party. And Republicans haven't yet been able to replicate pipeline programs like EMILY's List to recruit women and have a deep bench in lower offices to draw from.
"Any good year for Democrats tends to be a good year for women," said Jennifer Lawless, director of American University's Women & Politics Institute.
In the last presidential election, women made up over half of the electorate, and President Obama carried that bloc by 11 points. That cycle, Democrats also added to their Senate majority, and Republicans lost several winnable races after Missouri GOP nominee Todd Akin, when asked about abortion restrictions, made a comment that women rarely got pregnant by "legitimate rape."
After that, Republicans realized they had to talk to and about women more. Campaign committees trained male candidates on how to talk to their female opponents, and Republicans made efforts to recruit more women to run. Their efforts paid off, and in 2014, two more GOP women were elected as Republicans took control of the Senate. They were also able to push back on the Democratic argument that Republicans are carrying out a "war on women" — a message pushed hard by Sen. Mark Udall, who lost his 2014 re-election bid in Colorado to Republican Cory Gardner.
After 2014 success, the "war on women" re-emerges
But those efforts have been derailed by Trump. Earlier this year, the National Republican Senatorial Committee admitted in a leaked private memo to candidates and campaigns that Trump's rhetoric was a headache.
"Houston, we have a problem: Donald Trump has said some wacky things about women," wrote NRSC executive director Ward Baker. "Candidates shouldn't go near this ground other than to say that your wife or daughter is offended by what Trump said. We do not want to reengage the 'war on women' fight so isolate Trump by offering a quick condemnation of it."
But now, with the reality that Trump will be their party's nominee, it's becoming harder for candidates to distance themselves from him. Not all vulnerable incumbents have said they will endorse him for president, but not one has said they won't. Ayotte, in fact, tried to saddle the fence by saying she supports Trump as the GOP nominee but won't endorse him.
There's no question that Trump has a woman problem — a Gallup poll last month showed that 70 percent of women have an unfavorable opinion of Trump.
And the fear that he would alienate even more women in the general election was a main argument of anti-Trump groups in the primary, with one group running an ad that had women reading the insults that Trump had hurled at women in the past: "Bimbo. Dog. Fat pig."
And a New York Times story over the weekend explored Trump's "unwelcome advances, a shrewd reliance on ambition, and unsettling workplace conduct over decades" toward women.
Gender becoming a driving issue in 2016
De facto GOP presidential nominee Donald Trump has already accused likely Democratic nominee Hillary Clinton of "playing the woman's card."
"Frankly, if Hillary Clinton were a man, I don't think she'd get 5 percent of the vote," he said last month.
Clinton's campaign has capitalized on that, even selling official "Woman Cards" on her website.
"If fighting for women's health care and paid family leave and equal pay is playing the woman card, then deal me in," she has said on the campaign trail.
Democrats have worked to tie those comments to down-ballot races, too. An EMILY's List statement after Trump's comments hit GOP male incumbents over his "strategy to marginalize women by claiming that women voters only support women candidates because they are women."
"There are more women now for whom that concern [of electing a woman president] is maybe salient," she said. "And the notion of competing against Donald Trump, who in some ways is the complete antithesis of progress for women, might make the issue more salient for voters."
Deborah Ross, a Democrat who's challenging Republican Sen. Richard Burr in North Carolina, said the GOP nominee's comments about women would hurt him in that swing state — and she plans to make them hurt her opponent.
"The comments that Mr. Trump has come out with are not going to be helpful to him with women, but I really firmly believe that Burr's record won't be either, because it's in black and white," Ross said, pointing to his votes to de-fund Planned Parenthood and to scuttle paycheck fairness legislation.
Republicans argue that Clinton has plenty of weaknesses, too, including her own high negative ratings on favorability and trustworthiness.
"There is a reason Democrat candidates aren't lining up to campaign with Hillary Clinton. She is a toxic candidate whose failed leadership has put the security of our country at risk," said NRSC spokeswoman Andrea Bozek.
Nonetheless, Clinton still holds a narrowly positive favorability rating among women, and head-to-head matchups so far have shown she wins women in a general election by nearly 20 points.
It's no guarantee that a majority of female voters will elect a female candidate. For example, earlier this year Edwards lost to Van Hollen despite women making up the majority of the primary electorate.
And Lawless, the American University professor, said that it's yet to be determined how much Clinton could be a motivating factor on more women turning out, but that Clinton is embracing the historic nature of her candidacy in a way that she didn't until it was too late in her 2008 primary with Obama.
There's also hope that a Senate with more women could possibly lead to more congeniality in a notoriously divided Congress. A bipartisan group of women in the Senate meet regularly for supper, and during the 2013 government shutdown, it was Republican women who worked with their Democratic colleagues to broker a deal.
But to the women running this year, the historic nature of this election isn't lost on them either — not just the possibility of the first female president, but a potentially historic percentage of women in the Senate as well.
"I think it will be fabulous for this country to have more perspectives," said Ross, the Senate candidate in North Carolina. "But remember, 25 percent still doesn't represent the 50 percent of the population. We have to start somewhere, but I think there's always going to be room to grow."