The insurgency that swept Democrats into power in the U.S. House was led by suburban voters, both in the Twin Cities area and across the country.

They fueled wins by Democrats Angie Craig and Dean Phillips, who unseated Republican incumbents in the Second and Third congressional districts — which together wrap around the Twin Cities from the northwest to the southeast. The same thing happened in suburban Chicago, Houston, Dallas, Denver and Detroit, with Democrats at times defeating favored Republican House incumbents.

"I want change," Sherry Fredkove, of Plymouth, said Wednesday of her vote for Phillips. She said she liked his campaign's positive message and support for gay rights.

The suburban surge eroded part of President Donald Trump's 2016 coalition and, if it endures, could threaten both his own and his party's chances in 2020. It also illustrated the gap in Minnesota and other states between rural and urban/suburban voters.

In the Second District, Craig's margin this time painted a picture of shifting voter sympathies: She flipped 31 precincts that Republican Rep. Jason Lewis carried in 2016, including in Apple Valley, Hastings, Inver Grove Heights, Lakeville, Rosemount and Shakopee. Trump had carried the district by just 1 percentage point two years ago.

Suburban women, who are typically white and well-educated, often make the difference in such elections, said David Schultz, a Hamline University political science professor.

"They are the single most important swing voters in the United States — if they show up," he said.

They showed up Tuesday. National exit polls found that women accounted for 53 percent of voters and backed House Democrats over Republicans by a 21-point margin.

At Buzz Coffee & Café in Burnsville on Wednesday morning, Madison Winans, 22, a student and shift manager at the restaurant, said her votes were meant to express her dissatisfaction with the political climate. "It promotes hate, it promotes not getting along with people who are different from you, and I disagree with that completely," she said.

Craig said in an interview that she didn't shape her campaign message to appeal solely to women, but she found that many of them shared Winans' frustrations. They "really wanted to talk about how do we get back to a time in this country where we can work together," she said.

Craig became convinced of the emerging importance of women to her campaign at get-out-the-vote events in the last 30 days before the election.

She asked which participants were involved in their first campaign, and "inevitably a third of the hands in the room would go up," she said.

Turnout was one measure of voter enthusiasm in Craig's and Phillips' suburban districts. In the Second District, the number of voters was 156 percent higher than in the 2014 midterms. In the Third, it was 134 percent higher.

In 2016, Clinton won the Third District, 50 to 41 percent.

Phillips got a preview of women's preferences in September, when a KSTP-TV poll found that 54 percent of them supported his candidacy.

On Wednesday, Phillips said even he was surprised by his 11-point win over Republican Rep. Erik Paulsen, who had been re-elected four times by double-digit margins.

After becoming the first Democrat to hold the Third District seat since 1960, Phillips said he doesn't know if that means the west metro suburbs are becoming more Democratic, but "it certainly became more participatory."

"There's reason to be hopeful, there's reason to be optimistic," Phillips said.

Virginia Worthington, 60, of Minnetonka, said she's an independent who leans Republican and voted for Paulsen in 2016. This year, she voted for all Democratic candidates because she's frustrated with Congress and Trump.

Democrats shouldn't assume that voters like Worthington will stick with them, Schultz said.

Two decades ago, he said, suburban women concerned about family security often voted for Republicans because their candidates spoke about the quality of schools and health care. When the GOP veered away from those topics, he said, women began to vote for Democrats while suburban men stayed with the GOP.

Many skipped voting in 2016 because they disliked Hillary Clinton and Democrats' message, Schultz said, but on Tuesday they returned to the party to repudiate Trump. "If Democrats don't reach out to them and deliver, they will stay home" in two years, he said.

Alana Petersen, who ran Democratic U.S. Sen. Tina Smith's successful campaign, said that "this was a year we knew that women were going to show up," because health care was a dominant issue and women "were just energized."

During the 2017 Women's March, Petersen said, she realized "these women have to stay with us" in future elections.

David Gaither, a former Republican state senator from suburban Hennepin County who was a senior adviser to Jeff Johnson's GOP gubernatorial campaign, said Democrats here and across the nation succeeded in making Trump a central issue.

"People were more energized in the suburbs … to oppose the president rather than be for something," he said. But Gaither doesn't think the suburban shifts represent a broad political realignment.

His advice for future Republican candidates vying for suburban voters: "You need to be aspirational and give people a reason to vote for you."

Joe Peschek, another Hamline political scientist, said state Sen. Karin Housley, Smith's Republican rival, seemed to sense suburban trouble and adjusted her message at their Hamline debate days before the election.

Rather than repeating the GOP talking point that the Affordable Care Act should be repealed, Peschek noted, Housley instead answered a question by describing health care as a top issue and promising to address high costs.

The lesson of the 2018 campaign, he said, is that Minnesota "is not a deep-blue state at the presidential level," including among suburban voters.

"The Democrats had a good day [Tuesday] but I don't think it means Trump will be … less competitive in Minnesota than he was in 2016," Peschek said.

Marie Krengel, 23, who works at a Burnsville chiropractic clinic, isn't ready to write off the president or his party. In two years, she said, "I'll be asking what kind of people can I vote for who support the things that our president is doing well."

But to win over suburban women like Patty Riordan, Trump will have to change his tune. "He does not represent the people of this country and he needs to stop," said the 56-year-old veterinary assistant from Shakopee.

Star Tribune staff writer Jeff Hargarten contributed to this report.