New York Gov. Kathy Hochul will have to call a special election.
Rep. George Santos, the beleaguered Republican who represented New York's 3rd Congressional District, has officially been expelled from Congress over alleged ethics violations and other accusations of wrongdoing.
Santos steadfastly defended himself, including by labeling a scathing report from congressional investigators as a "smear."
But the vote to remove him passed with bipartisan support, and there are now 434 members of the House.
Questions are already swirling about who will replace him. The answer depends on who wins a special election for his swing seat.
New York Gov. Kathy Hochul, a Democrat, will have to call a special election within 10 days of Santos' expulsion, according to state law.
"I am prepared to undertake the solemn responsibility of filling the vacancy in New York's 3rd District," Hochul said just after Santos was expelled. "The people of Long Island deserve nothing less."
That election would occur within 70 to 80 days of Hochul calling it, and she would not be able to appoint someone to the seat before then. An empty seat would weaken Republicans' already narrow majority in the House.
There would be no traditional party primary where Democratic and Republican voters would choose from a list of candidates seeking to succeed Santos.
Instead, county leaders from each party would internally vote for and nominate candidates for the special election, according to New York election law. That would likely kick off a competitive courtship of local Republicans by many within Santos' own party.
Nassau County Democratic Chair Jay Jacobs told ABC News that a handful of candidates are being considered for their pick -- including former Rep. Tom Suozzi, 2022 Democratic nominee Robert Zimmerman and former state Sen. Anna Kaplan, among some others.
Suozzi and Kaplan have already launched 2024 primary election challenges for Santos's seat.
Since the district is mostly in New York's Nassau County but also includes parts of Queens, the consideration of nominees would be jointly made by Nassau and Queens Democrats, with Rep. Gregory Meeks leading the Queens cohort, in consultation with the Democratic Congressional Campaign Committee, House Minority Leader Hakeem Jeffries and Hochul herself, per Jacobs.
Nassau County GOP Chair Joe Cairo told Politico in late October that the county party will "select the best candidate, and we will give 110% effort as we do in every race." He said that the party had already heard from around 20 candidates.
A source familiar with the Nassau County Republicans confirms to ABC News that they consider around 15 candidates potentially strong contenders in the event of a special election and have been in touch with party leaders in Washington and hope to be able to produce a nominee within several days, should Santos be expelled.
Given the geographic makeup of the district, the Nassau County chapters of both parties would have the better part of the influence in who the nominee for their respective parties will be.
ABC News' Isabella Murray contributed to this report.