George Santos has disappeared. Two dozen candidates want his seat.

The expulsion of George Santos from Congress on Friday removed one major political headache for Republicans, but immediately paved the way for another: the party will have to defend its vulnerable seat in a special election early next year.

The race in New York is expected to be one of the most high-profile and expensive off-year House contests in decades. It has the potential to further reduce Republicans’ razor-thin majority and provide a preview of the broader battle for control of the House of Representatives next November.

“It will look like a presidential election for Congress,” said Steve Israel, a Long Island Democrat who once led his party’s campaign arm in the House of Representatives. “It becomes ground zero of American politics.”

Governor Kathy Hochul of New York has 10 days to formally schedule the election after Friday’s lopsided vote to oust Mr. Santos. But both parties expect the election to take place in mid-to-late February, just over a year after he first took the oath of office.

Unlike normal elections, party leaders in Washington and New York – not primary voters – will choose the Democratic and Republican nominees. They quickly went to work winnowing the field of potential candidates and were able to announce their picks within days.

Democrats were expected to coalesce around Thomas R. Suozzi, a proven centrist who held the seat for six years before Santos but gave it up in 2022 in a failed bid to become governor. Mr. Suozzi, 61, is a prolific fundraiser. and perhaps the best-known candidate that either party could put forward. Anna Kaplan, a former senator, is also a candidate and has positioned herself to the left of Mr. Suozzi.

The Republican field seemed more fluid. Party leaders said they planned to interview about 15 candidates, although officials briefed on the process said they were circling two top candidates, both relative newcomers: Mike Sapraicone, a retired New York Police Department detective, and Mazi Pilip , an Ethiopian-born former member. of the Israeli army.

Political analysts rate the district, which stretches from the outskirts of New York City to the heart of Long Island’s affluent Nassau County suburbs, as a mess. President Biden won the district by eight points in 2020, but it has since moved to the right in three consecutive elections as voters fearful of crime and inflation have turned to Republicans in droves.

Democratic strategists said they would continue to use Santos’ shyness to attack Republicans, blaming them for helping the former congressman’s rise. But regaining the seat could be more difficult than many Democrats ever hoped.

Local Republicans decisively distanced themselves from Santos last January, and the strategy has shown signs of success. When Long Island voters went to the polls for local elections last month, they delivered a Republican defeat that left Democrats scrambling to figure out how to rehabilitate a tarnished political brand.

“Anyone who thinks a special election on Long Island is a blow to Democrats has been living under a rock for the past three years,” said Isaac Goldberg, a strategist who advised the losing Democratic campaign against Santos in 2022.

“Politics is a pendulum,” he added. “Right now it’s on one side and it’s unclear when it will swing back.”

However, Republicans face their own challenges, especially in an idiosyncratic battle that will likely favor the party that can produce more voters. Democratic voters in the district have complained for months about their ties to Santos and are highly motivated to choose an alternative. It is unclear whether Republican supporters will feel the same urgency as their leaders.

“It’s been a frustrating year,” said Nassau County Republican Party Chairman Joseph Cairo. “I view this as just the beginning of righting a wrong, of moving forward, of electing a Republican who will serve the people right, of electing someone who is real – and not to believe.”

The outcome promises to have far-reaching consequences for the current Congress and the next.

After Santos’ ouster, Republicans have a razor-thin majority. Thinning it further could hamper their short-term ambitions to initiate an impeachment inquiry against President Biden and negotiate a major military aid package for Israel.

Whoever emerges victorious in February would also likely emerge as the frontrunner in next fall’s elections, giving his party momentum as they prepare to battle for six crucial swing seats in New York alone, including a total of three in Long Island.

Democrats believe that Mr. Suozzi, who currently works as a lobbyist, is best positioned to deliver results. During his stints as a congressman and Nassau County executive, he took conservative positions on public safety and affordability popular among suburban voters. And his combative primary campaign for governor last year could help him break the anti-democratic sentiment that has sunk other candidates.

Jay Jacobs, the Democratic leader for the state and Nassau County, said he still planned to screen several candidates, including Ms. Kaplan, a more progressive former senator who remains in the race even as other candidates dropped out and backed the Mr. Kaplan joined in. Suozzi.

Ms. Kaplan could get a boost from Ms. Hochul, who faced Mr. Suozzi in an ugly 2022 primary fight in which he questioned her husband’s ethics and called her an unqualified “interim governor.”

The governor has pushed Mr. Jacobs and Rep. Hakeem Jeffries of New York, the Democratic House leader, to reconsider whether Mr. Suozzi was their strongest candidate, especially given his reluctance to fully embrace abortion rights in the past. according to four people familiar with the conversations.

But it is unclear whether the governor would have the power to block Mr. Suozzi. Mr. Jeffries worked personally earlier this fall to lure the former congressman into the race, and Mr. Suozzi is close friends with Mr. Jacobs, who has told aides he is the likely choice.

The Republicans are proceeding more cautiously. They are wary of repeating their experiences with Santos, who secured the party’s support in 2020 and 2022 despite presenting them with a fraudulent resume and other blatant fabrications that they failed to detect.

This time, Republicans appear to be considering only candidates already known to party officials, and plan to hire a research firm to formally investigate potential nominees.

Campaign strategists in Washington are said to favor Mr. Sapraicone, the former police detective who made a small fortune as head of a private security firm. Mr. Sapraicone, 67, could afford to spend some of it on a campaign, but he would also be entering a race with virtually no name recognition or electoral experience.

Local Republicans pushed Ms. Pilip, a potentially groundbreaking rising star with a notable biography. She moved to Israel from Ethiopia as a refugee in the 1990s, later served in the Israeli army and, as a mother of seven, won a legislative seat in Nassau County at the age of 40.

Other wild-card candidates included Nassau County Comptroller Elaine Phillips; Kellen Curry, an Air Force veteran and former banker; and Jack Martins, a well-known senator who has previously run for the seat.

Mr Santos himself could, in theory, run as an independent candidate. But the task would be arduous and could jeopardize a more pressing priority: fighting charges that could land him in prison for up to 22 years.