Tom Suozzi, a former Democratic congressman, won a closely watched special House election in New York on Tuesday, narrowing the Republican majority in Washington and offering his party a potential playbook to run in key suburban swing areas in November.
His larger than expected victory in the Queens and Long Island district avenged a year of humiliation unleashed by the seat’s former occupant, George Santos, and stanched a trend that had seen Republicans capture nearly every major election on Long Island since 2021.
Mr. Suozzi, 61, fended off the Republican nominee, Mazi Pilip, in a race that became an expensive preview of many of the fights expected to dominate November’s general election, especially over the influx of migrants at the border and in New York City.
A well-known centrist, Mr. Suozzi distanced himself from his party, calling for harsher policies at the border and vowing to work with Republicans to fix a broken immigration system. Polls suggested the independent approach helped cut into Ms. Pilip’s advantage on the issue, as Democratic super PACs deluged her with ads attacking her as anti-abortion.
In the end, the race also became an old-fashioned local contest over turnout as a rare Election Day snowstorm blanketed Long Island. The 11th-hour twist most likely helped Democrats, who had turned out in larger numbers during early voting despite Republicans’ vaunted Nassau County machine.
With 93 percent of votes counted, Mr. Suozzi had won 54 percent of the vote compared with 46 percent for Ms. Pilip, according to The Associated Press.
Mr. Suozzi’s comeback will have an immediate impact in Washington. After he is seated, Speaker Mike Johnson can afford to lose only two votes on any partisan bill, an unwieldy margin that could limit Republicans’ election-year legislative agenda.
Addressing supporters in Woodbury, N.Y., on Long Island, Mr. Suozzi said his victory was an endorsement of the moderate approach he has championed for decades as a mayor, county executive and congressman.
“This race was fought amidst a closely divided electorate, much like our whole country,” Mr. Suozzi said. “We won because we addressed the issues and we found a way to bind our divisions.”
It was also a personal vindication for Mr. Suozzi, an ambitious career politician who has watched his fortune rise and fall over three decades in office. He gave up his House seat after three terms in 2022 to run for governor of New York, only to finish in a distant third place in the Democratic primary.
The cost of that decision became more clear as Mr. Santos was exposed as a serial liar and was ultimately charged by federal prosecutors with 23 criminal counts of campaign fraud and other charges. The House expelled him in December, after he had served nearly a year.
“Thank God,” Mr. Suozzi reveled at his victory party, boasting that he had overcome “all the lies about Tom Suozzi and the Squad, about Tom Suozzi being the godfather of the migrant crisis, about ‘Sanctuary Suozzi,’” and despite the Republican machine’s best efforts.
Republicans in New York and Washington always knew that retaining the seat vacated by Mr. Santos would be somewhat challenging given the Democrats’ modest advantage in registered voters and Mr. Suozzi’s name recognition. But party leaders were confident that they could prevail in a district that includes some of the nation’s wealthiest suburban enclaves.
But barely an hour after the polls had closed, they were conceding. Ms. Pilip, a 44-year-old county legislator, did not directly say whether she would run again against Mr. Suozzi in the fall, but implied she was not ready to step off the political stage.
“Yes we lost, but it doesn’t mean we’re going to end here,” Ms. Pilip told supporters at a watch party. “We’re going to continue the fight.”
There was little reason to believe the outcome would alter former President Donald J. Trump’s determination to make immigration a mainstay of his own campaign.
But it is likely to force Republican leaders and strategists mapping out the race for the House and Senate to reconsider the potency of the border issue that Ms. Pilip made the centerpiece of her campaign.
The issue was especially resonant here at the outskirts of New York City, and Democrats had privately warned in the race’s final weeks that it could be enough to defeat Mr. Suozzi. Voters were confronted with daily headlines about the spike in illegal border crossings and the more than 170,000 migrants who have arrived in New York. Just a week before Election Day, the New York City police commissioner warned that a “wave of migrant crime” had “washed” over the city.
Rather than write it off as an issue that favored Republicans, though, Mr. Suozzi made the migrant crisis a daily focus, along with cutting taxes, fighting crime and protecting abortion rights. He called for Mr. Biden to temporarily close the southern border and sought to show voters that he, too, saw the problem and wanted it fixed.
So when Ms. Pilip joined her party earlier this month in denouncing a bipartisan border deal that included many of the provisions they had demanded, such as expediting deportations and making it more difficult to claim asylum, Mr. Suozzi went on the offensive.
“Ms. Pilip points out there’s a problem! A problem! A problem!” he said during the race’s only debate. “But she has no solution.”
Voters took notice.
“He’s someone who doesn’t have to start from scratch,” said Rachelle Ocampo, 36, a health care communications director from Queens. “He has experience and he knows how to deal with local and federal issues.”
Mr. Suozzi sought to draw that contrast on issue after issue. He cast himself as a seasoned veteran ready to step in and find solutions: to reinstate the full state and local tax deduction sacrosanct to suburban homeowners, and to defend Israel amid its war with Hamas.
Republicans chose Ms. Pilip even though she was virtually untested, with few known policy positions and little experience navigating a nationally scrutinized race. It was a gamble that her life story as an Ethiopian-born former Israeli soldier would perfectly meet the political moment.
But Ms. Pilip’s inexperience showed throughout the campaign. She held vanishingly few public campaign events and declined invitations to the kind of forums and debates that would have introduced her to voters. In the one she did take part in, the Republican repeatedly raised her voice and left the moderator struggling to pin down her position on major issues like abortion and gun rights.
Though Mr. Suozzi did not make those issues a focal point of his own messaging, the Democrats’ main House campaign committee and House super PAC seized on the ambiguity in Ms. Pilip’s positions, burying her with $10 million in attack ads about abortion. Democrats ultimately outspent Republicans on TV two to one.
And Mr. Suozzi attacked Ms. Pilip over her evasiveness and qualifications, suggesting she was untested and unready for such a significant role.
“How can you run for Congress in this post-George Santos world and not be completely transparent?” he demanded on the debate stage.
Ms. Pilip, who forcefully broke with Mr. Santos a year ago, tried to reassure voters that she was a model of personal and public ethics. Many voters ultimately concluded she was just too much of a risk.
“We couldn’t have someone like Santos in again,” said Pierre Vatanapradit, an I.T. worker, as he cast his ballot for Mr. Suozzi on Saturday in Bayside, Queens. “We can’t let that happen again.”
But after weeks of campaigning, it was the most local of issues, a snowstorm, that electrified the race’s closing day, as both parties raced to turn out voters stuck at home.
This being Long Island, a suburban expanse where politics and public works have a history of mixing, Democrats were suspicious that Republicans who control the Nassau County government and each of its three townships might selectively clear paths for their voters.
“Of course we’re worried about where they plow the roads,” Jay Jacobs, the state Democratic Party chairman, said on Monday.
Bruce Blakeman, the Nassau County’s Republican executive, said he was “personally offended” that Democrats would question his administration’s integrity, and vowed to clear the streets equitably.
The Congressional Leadership Fund, the House Republicans’ main super PAC, even hired private snow plows to help clear the party’s best precinct areas faster, according to its spokeswoman.
In the end, it was not enough to close the gap.
Ellen Yan and Nate Schweber contributed reporting.