Jessica Leveto, chair of Moving Forward Together, a grass-roots group in Ohio, watches people sign petitions at the Harbor Perk Coffeehouse in Ashtabula. (Maddie McGarvey/FOR THE WASHINGTON POST)

When Susan Kroger decided to help launch a political activism group for women in her largely rural, pro-Trump region, she expected a few dozen liberal neighbors to show up.

But when she opened the doors at the group’s first community meeting in Sioux Falls, S.D., 100 people flooded into the room. Now nine months later, Kroger says the group has quickly grown to 2,300 active members.

It’s a story emerging across Trump country, where left-leaning grass-roots groups have popped up in some of the reddest parts of the nation — a sign that “the resistance” has gone rural.

Most surprisingly, Kroger said, some of her newest members are disappointed Trump voters. The uncertainty over health-care policy has become a top issue driving first-time activists to join their ranks, Kroger and other grass-roots organizers said.

“The exciting thing about our events is that every time we hold one, I always ask ‘Who here is new?’ and about half the people raise their hand,” said Kroger, co-chair of LEAD South Dakota, an abbreviation for Leaders Engaged and Determined. “I’ve heard from a few women who voted for Trump and have since had a change of heart.”

(McKenna Ewen,Whitney Leaming,Whitney Shefte/The Washington Post)

Donald Trump won 60 percent of rural voters in the 2016 presidential election, slightly more than Mitt Romney in 2012 and Sen. John McCain (R-Ariz.) in 2008. But since then, the president’s national approval rating has slipped to 39 percent in late July, according to Gallup, helping to explain why political activism groups are flourishing in some places that turned out heavily in Trump’s favor during the election.

Results of a Washington Post-Kaiser Family Foundation poll suggest that Trump has long been on shaky ground in parts of rural America. Rural respondents to the April poll were as likely to strongly disapprove of Trump’s job as president as to strongly approve, 30 percent each. When broken down by gender, rural women reported a slightly higher disapproval than rural men, perhaps why many of the grass-roots groups are led by women.

Kelly Sullivan, a 30-year-old restaurant server in Sioux Falls and member of LEAD, noted that rural America has long been politically diverse, but the recent surge of political activism has made it more noticeable.

“People like us in smaller places and people that are in the rural communities, we’re just the same as the big city slickers,” Sullivan said of her fellow rural activists. “The feeling that we’re not being represented, or the feeling that the current administration is doing things that we disagree with, we’re on the same page as the people who are in the big cities.”

Trump won all but five of the 66 counties in South Dakota — including Minnehaha, the county in which Sioux Falls, a city of about 170,000 people, is located. The state gave Trump one of the highest approval ratings in the country during his first six months in office — 54 percent, according to Gallup.

Still, Sullivan said a resistance effort has been building in the state since Trump was elected. In January, she co-chaired a local march in conjunction with the national women’s march, attracting nearly 3,300 demonstrators to downtown Sioux Falls in 30 degree temperatures. Sullivan said the experience — seeing the sea of like-minded people — transformed her from a person who never dreamed of being politically active to someone who uses her spare time to call lawmakers. She is also preparing for her own run for a state legislative seat next year.

LEAD South Dakota has a nine-person board of directors and committees tasked with monitoring state legislative activity, candidate recruitment and other efforts. So far, the group is working with 75 candidates who are interested in running for office and is planning to break into chapters across the state to help manage its rapid growth.

“I was absolutely surprised to see the groundswell here in South Dakota,” Kroger said. “I have some experience in politics so I know how it feels to be the little guy in a state where you very much feel like the minority.”

In Ohio, Moving Forward Together Ashtabula County, a grass-roots group affiliated with the nationwide Trump resistance movement Indivisible, has also exceeded its leader’s initial expectations.

When Moving Forward hosted its first community forum in May, a panel to discuss concerns about health care and immigration, “I was afraid it would be three people and a sign,” said the group’s chair, Jessica Leveto. The forum took place in Jefferson, Ohio — a rural town of about 3,000 people, in a county that cast 57 percent of its votes for Trump.

Nearly 125 people showed up, Leveto said.

Moving Forward started in a local coffee shop in February, and within two weeks — with a few social media posts and through word of mouth — its numbers outgrew the space, said Leveto, an assistant professor of sociology at Kent State University at Ashtabula.

Leveto points to May’s Affordable Care Act repeal vote as an indicator of her group’s growing muscle. Despite routinely following party line votes, Ashtabula’s congressman, U.S. Rep. David Joyce (R-Ohio), was among the 20 Republicans who did not vote in favor of the repeal.

“I think we had something to do with that,” Leveto said. “I don’t think it was just our group, but the groups in the district. I think there were a lot of phone calls.”

Joyce did not return requests for comment.

Rural political action organizers say a health-care revision is a dominant issue that has galvanized their groups because members are concerned that rural citizens will be largely affected by any changes. Leveto said, specifically, many attendees at her group’s May event wanted answers on how an overhaul might effect the area’s fight against the opioid crisis.

In The Post -Kaiser poll, 95 percent of rural respondents said Medicaid is very or somewhat important to their communities. Thirteen percent said they rely on Medicaid themselves, compared to 10 percent of their urban and suburban counterparts, a statistically insignificant difference.

“Our communities are at risk, these are things that even in the South, we see the need to stand up and fight for the people in our community and I think that’s something that transcends region,” said Mandy Fowler, founding member of the Kudzu Coalition of West Alabama, a growing political action organization.

As an Indivisible group, the Kudzu Coalition hosts local forums, provides advocacy training and coordinates phone calls and emails to legislators. Its cornerstone event is a weekly demonstration called “Show up Shelby,” when members gather in the lobby of Republican Sen. Richard C. Shelby’s Tuscaloosa office to call for a town hall meeting.

The group uses the name of the Kudzu plant, an invasive species common in the South that is resistant to most herbicides. Fowler said it’s an appropriate moniker in a state where nearly 63 percent of voters backed Trump.

“We grow fast and we connect and we flourish in an area where it can be difficult for others to thrive. We are hard to get rid of,” Fowler said.

The group spun off from a closed Facebook page that connected Alabamians who wanted to discuss their dissatisfaction with the election.

“Especially in a red state, it can make things uncomfortable at work, school, places like that, where people are more Republican,” said Kisha Emmanuel, a graduate student in Tuscaloosa who began following the page soon after the election. She’s now an active member of the Kudzu Coalition.

As the number of page followers grew, Fowler said she wanted to mobilize the energy she was seeing online and began in-person meetings in December.

Small town and rural mobilizing will probably yield results, said James Simmons, a professor at the University of Wisconsin at Oshkosh who recently researched voter trends and attitudes in rural areas.

“If you look across the country, and you look at the real change that has happened over the last five or 20 years, it hasn’t happened at the national level, you see policy driven at the state level,” Simmons said. “If you’re talking about populist discontent, this is where it was bubbling.”