Yee Leng Xiong, a 29-year-old nonprofit executive, has been an elected official in Wisconsin since he was a teenager. From a north-central county known for ginseng farming and downhill skiing, he has served on the local school board, the Marathon County board and the village board of trustees in Weston, population 15,000.

But he is a Democrat, and running for a seat in the state Legislature in a solidly Republican district had always seemed a little outlandish.

Until this year.In February, new legislative maps in Wisconsin were signed into law after more than a decade of partisan wrangling and legal battles. The new maps undid the gerrymander that had helped Republicans keep control of both state legislative chambers since 2012. The 85th Assembly District in Marathon County, where Xiong lives, is no longer a Republican-leaning seat: It is a toss-up.

“This idea came to reality when the maps changed,” Xiong said in an interview last month.

On Saturday, Xiong announced a run for state Assembly, hoping to unseat the Republican incumbent, Rep. Patrick Snyder, a popular candidate who most recently won reelection by more than 12 percentage points.

The new legislative maps have created a particular hardship for Snyder, who was dismayed to learn that he had been drawn out of his own district by a block and a half. He said he plans to rent a studio apartment in the newly drawn 85th district.

“We’ll amp it up,” he said of his campaign. “We are very serious about maintaining this seat.”

The state’s residents have long been a close mix of Democrats and Republicans, which makes Wisconsin a crucial swing state in presidential elections and means statewide races are often fiercely contested. The reshaping of the maps is expected to suddenly return many legislative races to the realm of true competition as well.

After more than a decade of languishing in the minority in the state Legislature, Democrats are now in a position to vie for political power with Republicans, who currently hold about two-thirds of the seats in both the Senate and the Assembly.

“We are on offense,” said Rep. Greta Neubauer, a Democrat and minority leader of the state Assembly. “We absolutely see a path to the majority.”

The new maps — ordered by the Wisconsin Supreme Court in December after finding the previous ones unconstitutional — reflect a near-split between Democratic- and Republican-leaning districts: 45 are Democratic-leaning, 46 are Republican-leaning, and eight are likely to be toss-ups.

Democrats would need to flip 15 seats to gain a majority in the Assembly, although they do not view the state Senate — whose elections are staggered — as within reach this year.

With the fall election just over six months away, the scramble to take advantage of the new maps is underway. Democratic officials said they have been fielding dozens of inquiries from potential candidates who are coming off the sidelines, people like Xiong who have been waiting for an opportunity to run for office but have felt stymied by gerrymandering. Under the new map, the 85th Assembly District is nearly evenly split between Democratic and Republican voters, putting it within reach for Xiong.

Republicans say they expect to lose seats under the new maps but are fighting to hold on to as much as they can — including majority control.

During a typical election year, Snyder would start knocking on doors in August to talk to constituents and ask for votes. This year, he is starting in July.

“I do expect a little bit more of an aggressive campaign,” he said.

Democrats say they are planning to hold fundraisers across the state in every competitive district, anticipating that their campaign budget will be several times what they have spent in recent cycles on Assembly races.

“We’ll be in parts of the state where we have not been in a while,” Neubauer said.

The implications for elections under the new maps go beyond Wisconsin’s Legislature.

If Democrats are successful in improving turnout, particularly in newly competitive districts, there is a chance they could help boost President Joe Biden’s reelection bid in Wisconsin.

National political groups have taken notice with promises of funding. The Democratic Legislative Campaign Committee said in February that it would double its investment in Wisconsin state legislative races, part of a broader effort to flip party control of chambers in states including Arizona, New Hampshire and Pennsylvania.

Republican leaders suggested that the changes in Wisconsin’s maps were not going to shift control and that Republicans would continue to see success in November. “Democrats are about to find out that their consistent record of failure in recent election cycles at the state legislative level in Wisconsin had nothing to do with maps, and everything to do with their out-of-touch policy agenda,” said Dee Duncan, president of the Republican State Leadership Committee.

In Marathon County, Xiong said he was anticipating a battle over the Assembly district that he hopes to represent.

He described himself as a moderate Democrat who is a gun owner and fiscally conservative. Xiong, who is a son of immigrants from Laos and executive director of the Hmong American Center in Wausau, would be the first Hmong American to serve in the state Legislature if elected.

With a new legislative map creating a more even playing field, he said, he hopes that it will lead to elected Republicans and Democrats finding common ground.

“It’s going to create competition,” Xiong said, “and it will force us to build compromise.”