Where Are All the Manhattan Voters in August? Try the Hamptons.

AMAGANSETT, N.Y. — In the lush town green here one recent morning, waiting to get her nails done, sat just the kind of Manhattan Democrat whose coveted vote could tip the balance in Tuesday’s blockbuster primary involving two lions of Congress, Jerrold Nadler and Carolyn Maloney.

Only the woman in question, Judith Segall, said she was in absolutely no rush to leave this exclusive bastion of sand dunes, $10 heirloom tomatoes and seasonal city transplants, and return to her Upper East Side home.

“I’m not coming in to vote. That’s the problem: Nobody here is going to come in just to vote,” said Ms. Segall, a retired accountant with a city accent who spends her summers out here, and likes Mr. Nadler. “It’s insane. What’s this voting in August?”

New York City may be a center of the political universe this summer, as Mr. Nadler and Ms. Maloney, two powerful longtime allies, face off in a newly reconfigured Manhattan district, and a dozen other Democrats scramble to claim a rare open seat connecting Lower Manhattan and Brownstone Brooklyn.

But in a twist befitting two of the wealthiest districts in the United States, the races could well be won or lost miles outside the city, in places like the Hudson Valley, the Berkshires and, above all, the sandy coast of eastern Long Island, where otherwise reliable voters like Ms. Segall decamp in droves each August to spend the final weeks of summer in second homes and vacation rentals.

That reality has prompted an unusual and expensive shadow campaign — complete with beach-themed mailers, sophisticated geolocation tracking for tailored ads targeting second homes and at least one Hamptons swing by Ms. Maloney — to see who can prod more of their would-be supporters off their beach chairs and back to the city, or at least the local post office.

With low turnout predicted, political operatives say as few as a thousand lost votes could be the difference between a narrow victory and a loss.

The exodus is most glaring in the 12th District, where Mr. Nadler and Ms. Maloney were drawn together after three decades serving side by side and are now fighting (alongside a third candidate, Suraj Patel) over uptown voters who like them both.

Some 35,000 Democrats have received mail-in ballots there so far, according to the New York City Board of Elections, a large proportion of them people over 65, and many Upper East and West Siders who flee their apartments when the weather warms. By comparison, the board said that just 7,500 mail-in ballots were distributed for all of Manhattan during the 2018 midterm primaries, which were held in June.

Another 21,000 Democrats have received absentee ballots for the primary in the neighboring 10th District, far more than any other district but the 12th. The 10th includes wealthy areas like Greenwich Village, Park Slope and Brooklyn Heights — as well as Orthodox Jewish communities in Borough Park — whose residents also tend to skip town.

“The last two weeks of August, this is actually where many people are,” said Jon Reinish, a Democratic political strategist, who is among a torrent of temporary city transplants who have slipped away to the Hudson Valley town of Rhinebeck.

He had a word of advice to Democratic vote hunters, particularly Ms. Maloney, whose East Side base even relocates some of its favorite restaurants out to Long Island for “the season.”

“As opposed to pounding the pavement around the 86th Street and Lexington Avenue subway stop, Carolyn Maloney may be better served campaigning outside the entrance to Sagg Main Beach or along Jobs Lane in Southampton,” he said, only partially in jest.

Hamptonites are already accustomed to national politicians descending each summer for ritzy fund-raisers and seafood raw bars: Vice President Kamala Harris; Beto O’Rourke, a Texas Democratic candidate for governor; and New York’s candidates for governor were all here recently. But given the timing of the Aug. 23 congressional primaries, they appear to be relishing their moment of heightened electoral influence.

“If they are serious about wanting to be re-elected, they should be out here,” said Gordon Herr, the chairman of the Southampton Town Democratic Committee and a former city resident who moved out east full time 16 years ago. He said many city residents he’s spoken to “are very conflicted” over who to vote for and could use the extra nudge.

New York almost never holds elections in August. But that changed this year after the state’s highest court tossed out newly drawn maps favoring Democrats as unconstitutional, and a rural judge decided to split that state’s primary calendar in two to allow time for a court-appointed expert to draw new, neutral lines.

The result put Mr. Nadler and Ms. Maloney on a collision course and opened a fresh seat next door; it also means New Yorkers are being asked to go to the polls twice in two months.

Voters who will be in the city on Election Day undoubtedly remain the majority, and the campaigns’ chief focus. But tracking those headed outside New York has been an uncommonly high priority, particularly for Mr. Nadler and Ms. Maloney.

Mr. Nadler’s campaign sent partially filled-out absentee ballot applications to 50,000 potential supporters earlier this summer anticipating their travel, and is now using digital geolocation data to serve advertisements to likely voters that it can see are in the Hamptons or the Berkshires, specifically reminding them to drop the documents in the mail before it’s too late.

Another glossy campaign mailer featured an Atlantic Ocean beach: “Away on August 23rd?” it read. “Don’t miss your chance to vote for Jerry Nadler.”

“It’s something that we worried about from the beginning,” said Mark Guma, Mr. Nadler’s lead strategist, who estimated that as many as a fourth of all votes in the race might be cast by mail.

The undertaking is not cheap. The campaign reported paying Mr. Guma’s firm $270,000 to date for the mail program and other services.

Ms. Maloney’s campaign has made a similarly large investment and has deputized local supporters to help track down summer voters to drop absentee ballot applications and other campaign literature at their second homes. (Both campaigns deemed city-style canvassers at exurban farmers’ markets and beaches inefficient.)

In late July, Ms. Maloney made the trip to work the Montauk Highway herself, attending at least one fund-raiser, a meet-and-greet at the home of a supporter, and a Q. and A. at the Hampton Synagogue, a lively forum for politicians each summer.

“It’s a huge challenge,” Ms. Maloney said, adding that she was “absolutely” concerned about getting her supporters to the polls. “A lot of voters are out there. I hope they vote.”

In some of the leafy villages of the Hamptons this past week, the results appeared to be mixed. Many voters said they planned to head back into the city for early voting or Primary Day.

As he lounged on a bench with an iced coffee in Southampton, one of them, John Lewin, said he’d gotten multiple phone calls from Mr. Nadler’s campaign reminding him to vote and had firm plans to return to his home on the Upper West Side on Primary Day.

“I like going physically — old school,” said Mr. Lewin, a lawyer.

He conceded the two incumbents were “probably not” that different, but Mr. Nadler had his vote. “It’s like me going to Zabar’s,” he said. “I know where everything is. That’s Jerry Nadler.”

But in many cases, the campaigns have struggled to be heard over the pleasures of vacation: tennis lessons, swimming, long hikes in the Catskill and Berkshire mountains, meals to be cooked.

“There’s this weird thing out here, everyone’s doing a million things to squeeze everything in that feels good right now after the pandemic,” said Julie Dermer, a Manhattan fitness instructor who relocates to the Hamptons each summer to teach. “They’re not ready to work for such a cause right now or a person.”

Ms. Dermer put herself in that camp, and initially said she was not sure she would vote next week (though later followed up to say she would). She said she was open to either candidate. “Certainly if I’m ever near the voting booth, I’ll go,” she said.

Mr. Patel’s campaign has made its own effort to chase absentee voters, even mailing first-class letters to registered voters overseas. But with a message of generational change, Mr. Patel, 38, is betting on younger voters less likely to own a second home to deliver him an upset in the primary. He has spent the final days of the campaigning trolling around Manhattan in an ice cream truck.

His advisers said there were signs in early voting data that showed the mail-in vote may make up a smaller proportion of the electorate than first anticipated, though it may be too early to tell. As of midweek, around 12,000 absentee ballots had been returned in the 12th District and roughly 4,800 in the 10th District. Each race could end up with between 60,000 and 80,000 or more votes.

In some cases, voters have taken it upon themselves to try to beat the summer apathy.

One Lower Manhattanite in the 10th District, a business owner and actress who often spends summers in the Hamptons or abroad, said she and her family would vote in person. But she was worried others might tune the races out given the unusual election date and profusion of candidates.

“There is no doubt confusion,” said the actress, Sarah Jessica Parker. “I will start encouraging all I know to make sure they have their ducks in a row.”