They marched, they ran, and on Election Day, they won.
Women led a parade of victories and unexpected upsets Tuesday to win control of the House for the Democrats.
It was the culmination of two years of anger, frustration and activism driven by women appalled by Donald J. Trump’s election and presidency. Women poured into grass-roots groups determined to regain Democratic control of Congress and flooded organizations that trained them to run for office. As candidates, women broke the rules and upended conventional political wisdom. As activists, they expanded the definition of women’s issues beyond education and reproductive rights to include health care, immigration, gun violence and the environment.
It was a litany of historic firsts, most of them by Democrats: In Massachusetts, Ayanna Pressley became the first woman of color in her state’s congressional delegation. Rashida Tlaib in Michigan and Ilhan Omar in Minnesota will be the first Muslim women in Congress. Sharice Davids toppled a Republican man in Kansas and Deb Haaland prevailed in New Mexico, becoming the first Native American women elected to Congress. In Tennessee, Marsha Blackburn, a Republican, became the state’s first woman elected to the Senate.
But several prominent women were also defeated — Senator Claire McCaskill lost to Josh Hawley in Missouri, Amy McGrath lost a closely watched House race in Kentucky, and Senator Heidi Heitkamp lost her re-election race in North Dakota. Stacey Abrams of Georgia, who had hoped to become the first black woman in the country to be elected governor, was trailing her Republican opponent, Brian Kemp.
Pennsylvania, which had no women in its 21-member congressional delegation, will now have four. Democratic women flipped three Republican-held seats: Mary Lou Scanlon, Chrissy Houlahan and Susan Wild; and Madeleine Dean won an open seat.
Two women helped Democrats pick up seats in Florida: Debbie Mucarsel-Powell and Donna Shalala, a member of former President Bill Clinton’s cabinet. Ms. Houlahan was one of four female military veterans and political newcomers to win seats for Democrats; the others were Mikie Sherrill in New Jersey, and Elaine Luria and Abigail Spanberger in Virginia. Lauren Underwood in Illinois helped Democrats produce another unexpected victory.
“I urge you to work for a better future long after tonight,” Ms. Sherrill said before a thunderous crowd that included dozens of women who had spent months canvassing and phone banking. “The thousands of women who are ready to join me to make sure we have a better future for our kids, for New Jersey and for the United States of America.”
She told how she had asked her daughter Maggie, the oldest of her four young children, if she was “O.K. with this.” Her daughter, she said, “asked, ‘If you don’t run, who will?’”
It was striking to consider just how far women had come since the women’s marches across the country the day after President Trump’s inauguration. Women like Ms. Sherrill and Ms. Davids had started as long shots, but their victories seemed assured by Election Day.
With a Democratic majority in the House, women will wield more institutional power — Representative Nancy Pelosi is expected to beat back a leadership challenge to again become speaker, the only woman to ever hold that post. Representative Nita Lowey, Democrat of New York, would chair the Appropriations Committee, and Representative Maxine Waters, Democrat of California, would chair the Financial Service Committee.
The energy among Democratic women made it harder for Republican women to emerge as candidates.
And in the first big defeat of the evening for Republicans, Representative Barbara Comstock lost by wide margin to a Democrat, Jennifer Wexton, in the Virginia suburbs. Ms. Comstock, a prolific fund-raiser, had survived previous challenges in the blue district.
A challenge from a Democratic woman threatened the highest-ranking Republican woman in the House, Representative Cathy McMorris Rodgers of Washington.
According to figures tallied by the Center for American Women and Politics at Rutgers, 428 women ran for Congress or governor as Democrats, compared with 162 Republicans. Of these, 210 Democratic women and 63 Republican women remained nominees by Election Day.
Republican women were animated by their own issues, including fears of borders being overrun and a backlash to the #MeToo movement.
Kelly Dittmar, a political scientist at the Rutgers center, the surge of women had changed American politics.
“For some women, that meant not waiting their turn,” she said. “For other women, it also meant running in ways that embraced gender and race as an asset they bring to candidacy and office-holding, instead of a hurdle they have to overcome to be successful in what has been a man’s world of electoral politics.”
This cycle, the first since the defeat of the first female major party presidential candidate, many women ran without being asked. And they ran differently, ignoring the timeworn advice to female candidates to talk about your résumé and pretend you don’t have a personal life. Instead, they featured their children in ads, offered personal testimony about sexual harassment and abuse, and opened up about family struggles with drug addiction and debt, to connect to many Americans with the same struggles.
Women shattered records and precedents. One-third of the female nominees for the House were women of color, the highest ever. A record number of women faced off against other women, from Arizona to New York. Ms. Pressley in Massachusetts and Alexandria Ocasio-Cortez in New York were among women who defeated long-serving white male incumbents in party primaries and won tonight.
Candidates like Ms. Sherrill, Ms. McGrath and Katie Hill, who was running for a House seat in California, raised staggering amounts of money, though women still raised less, on average, than men. And women played bigger roles as donors, giving 36 percent more money to congressional campaigns than in 2016.
But as many more women ran, it was perhaps inevitable that many more would lose, as well. Heightened political activism in the Trump era brought out many more men running for office, too, and many of the female candidates were Democrats running in districts that are gerrymandered or all but assured to vote Republican. In Florida, two challengers, Lauren Baer and Mary Barzee Flores, lost to Republican incumbents.
Despite being more than half the population and the voters, women were still less than a third of all candidates for Congress, the governors’ offices and other statewide executive seats.
Women running for governor, from Idaho to Texas to Maine, faced the steepest hurdles of all. Twenty-two states have never elected a woman as governor — six states have female governors now — and research has shown voters are more reluctant to choose women as chief executives than as legislators. Gretchen Whitmer was elected governor in Michigan, Laura Kelly in Kansas and Michelle Lujan Grisham in New Mexico.
In a political season in which disgust with Washington runs high, many women hope their lack of traditional political credentials will enhance their outsider appeal: Jahana Hayes, a former teacher of the year, was a surprise winner of a Democratic House primary in Connecticut and on Tuesday became the state’s first black woman elected to Congress.
The elections also could bring a younger generation to Washington: Ms. Ocasio-Cortez as well as Abby Finkenauer, a Democrat running for a House seat in Iowa, are both in their late 20s.
President Trump was elected by the largest gender gap on record, and women have moved even more leftward throughout the first two years of his presidency, even as men have gravitated toward the Republican Party.
In a Gallup survey of registered voters in September, while men favored Republicans over Democrats, 50 percent to 44 percent, women preferred Democrats by 58 percent to 34 percent. That 24-point split had widened from eight points in June. The gap between the genders is even more striking among millennials. Earlier this year, a Pew poll found that 70 percent of millennial women affiliated with or leaned toward the Democrats, up from 56 percent four years ago. Just under half of millennial men did.