It’s a 2024 election battleground where millions of dollars are being spent and big names in American politics are popping up. But it’s not in the Rust Belt. And it isn’t Georgia or Nevada, either.

It’s Long Island, a suburban stretch east of New York City, home to some 3 million people who might have an outsized role in choosing which party controls Congress. Democrats are just a few seats shy of winning a majority in the U.S. House and the island, just a train ride from liberal Manhattan, has emerged as an improbable stage for some of the most contested races this year.

The region is also an unlikely center of Republican power in deep blue New York.

In some ways, the issues that have pushed Long Island to the right in recent elections could animate any battleground state suburb this November, with GOP candidates framing their campaigns on crime, immigration and the economy. The move by Democrats to replace President Joe Biden with Vice President Kamala Harris at the top of the ticket last month added another unpredictable variable to downballot races all over the country, with both parties scrambling to assess the impact.

But here, Republicans have seized momentum by harnessing suburban backlash over progressive policies in New York City, casting themselves as a dam that can stop the left from swamping Long Island with liberal excess.

The strategy has proven successful so far. Long Island Republicans have dominated local races in Nassau and Suffolk counties and control all but one of the island’s congressional seats. New York as a whole may vote reliably Democratic, but there's nuance to be found not far from Manhattan.

“The Democrat Party is no longer the Democrat Party as we knew, or I knew, growing up. It’s changed. It’s become much more to the left, progressives are taking over,” said Joe Cairo, chairman of the Nassau County Republican Party and an architect of Republican wins on the island. “People move out here, they’re fed up with the city.”

Republicans notched perhaps their most prominent victories on Long Island two years ago, as the city was reeling from a pandemic-era uptick in violent crime. Suburban voters were pounded by a steady stream of apocalyptic headlines and TV commentary suggesting an urban hellscape next door.

Republicans swept all four of the island's congressional seats, and a Long Island Republican, former U.S. Rep. Lee Zeldin, nearly landed a major upset in the governor's race — an office the GOP has not held in years.

Democrats, though, now see Long Island as a prime opportunity to recapture congressional seats in their bid to reclaim a House majority.

The party is coming off an encouraging win in a winter special election for the seat that became vacant when George Santos was expelled from Congress. Democrat Tom Suozzi, running as a centrist, defeated a Republican county lawmaker.

Republican U.S. Rep. Anthony D'Esposito, who is seeking a second term in a district just east of Queens, is expected to face a serious challenge from Democrat Laura Gillen, whom he defeated by less than 4 points in 2022.

Democrats have also issued dire warnings about what a federal government unified under Republicans could mean for abortion access, following a formula that has worked elsewhere to drive up turnout on their side.

“The legacy of the Dobbs decision, overturning Roe v. Wade, is starting to play out and really resonate with people who care about access to reproductive health care,” said Gillen, a former town supervisor.

Democrats on Long Island also hope to benefit from having Harris as their presidential nominee, with voters energized around a female candidate in a year when protecting abortion access is on voters' minds.

“Harris' accession to the top of the ticket has energized more than just the presidential race. It has injected a lot of hope in Democratic congressional campaigns where, as Biden was sinking, they saw their prospects going down as well,” said Larry Levy, dean of the National Center for Suburban Studies at Hofstra University on Long Island.

In New York, Democrats have tried to recalibrate after losses on Long Island in 2022, gearing their political strategy toward moderates.

New York Gov. Kathy Hochul has made crime a major focus and won concessions from progressives at the statehouse to tweak bail laws and strengthen criminal penalties for assaulting retail workers. In June, Hochul also made an 11th-hour decision to suspend a new toll for drivers entering Manhattan following heavy pushback from commuters.

Republicans downplay Suozzi’s recent victory, arguing the former congressman faced a relative unknown in a low-turnout special election on a cold, snowy day. Even so, Democrats believe Suozzi’s centrist approach has given their candidates a Long Island roadmap.

“You can’t ignore the issues people care about and you need to seize the vital center to win,” said John Avlon, a former CNN anchor and Democrat who is running against Republican U.S. Rep. Nick LaLota in a congressional district on eastern Long Island that’s been controlled by Republicans for a decade.

But it may be difficult for Democrats to shake the perception that they’re too progressive for some suburban voters.

Joe Gillespie, a 58-year-old electrician who commutes from Long Island’s Levittown to construction sites in New York City for work, said Democrats have become too liberal on crime, immigration and social issues to convincingly change course.

“They’ve gone so far to the left,” Gillespie said. “People are going to assume that they’re just doing that to get back the votes right now.”

Candidates will also have to contend with a figure looming over all the 2024 contests: former President Donald Trump.

The former Republican president is often greeted as a hero in parts of Long Island by the many blue-collar workers and New York City police officers and firemen who live in the suburbs. Trump flags fly on both manicured front lawns and from the back of pickup trucks.

Trump won Suffolk County on the eastern half of the island in 2016 and 2020, though his margin narrowed last time. He lost Nassau County in both elections, lagging 15 points behind Biden in the district where D’Esposito now faces Gillen. Whether Trump will hurt or help Republicans on the island this year remains to be seen, but both parties are optimistic.

Violent crime has dropped substantially in the New York City metropolitan area since the 2022 election, but Republicans continue to raise it.

Nassau County Executive Bruce Blakeman, a Republican, has sought to score points with suburban parents by leading an effort to ban women’s and girls’ sports teams with transgender players from using county-run parks and fields. And while it may not have much practical impact, the push mirrors an attack line that has worked for GOP leaders elsewhere.

The new rules are now the subject of a legal battle. The state’s Democratic attorney general, Letitia James, argues that the ban violates state anti-discrimination laws, but Blakeman said support for the policy locally has been “overwhelming.”

“My phone and my text messages and emails are running probably eight in favor and two against,” he said. “The Democratic Party has drifted so far to the left that independent voters and common sense Democrats can no longer support their positions,” he said.