What happens to N.J. Sen. Bob Menendez’s seat after his conviction?

New Jersey Democrat Bob Menendez on Tuesday became one of just a handful of U.S. senators to be convicted of a crime while in office — and the first ever found guilty of being an agent of a foreign government — raising questions about whether he will be able to serve out the remainder of his term.

Within minutes of the jury’s verdict, Senate Majority Leader Chuck Schumer had called for Menendez’s resignation, while New Jersey Gov. Phil Murphy urged the Senate to expel Menendez if he refuses to leave.

Menendez, 70, did not comment on his political plans in brief remarks after the jury found him guilty of accepting bribes of gold and cash from three New Jersey businessmen and acting as a foreign agent for the Egyptian government. He maintained his innocence, saying: “I have every faith that the law and the facts did not sustain that decision, and that we will be successful upon appeal.”

Here is a closer look at what could happen to Menendez’s seat now.

Expulsion

The Constitution gives Congress the power to punish its members and requires a two-thirds majority to expel a lawmaker. Democrats have a tenuous hold on the majority thanks to independent members caucusing with them. Whether they might decide to pursue expulsion isn’t clear.

“There is no requirement or rule requiring expulsion votes or hearings if a member is convicted of a crime,” according to Josh Howard, assistant historian at the Senate Historical Office. “It would be up to the Majority Leader and/or Senate Select Committee on Ethics to determine next steps, if there are any.”

What is certain is that expulsion hasn’t happened in more than 160 years. The last such vote was in 1862, according to the Senate, and by far most of the 15 senators who were expelled were booted for supporting the Confederacy.

Resignation

Other senators throughout history who faced possible expulsion opted instead to resign.

Prior to his conviction, Menendez had already bucked pressure from leading Democrats in his state as well as Senate colleagues to resign.

The last senator convicted of a crime while in office, Ted Stevens of Alaska, also refused to quit and was ousted in an election, only to have his conviction wiped out by an appeals court over alleged prosecutorial misconduct.

The last senator to resign was Harrison Williams Jr., also a New Jersey Democrat who was convicted of bribery. He resigned in 1982 before the Senate could vote on whether to expel him.

What if there’s a vacancy?

New Jersey law allows the governor to appoint a senator to fill the vacancy, though it’s not required.

Murphy said after the verdict that in the event of a vacancy: “I will exercise my duty to make a temporary appointment to ensure the people of New Jersey have the representation they deserve.”

He did not say who that would be. The Democratic Party has already nominated Rep. Andy Kim as its candidate in November.

Would Murphy tap Kim so he could potentially gain some seniority ahead of a possible victory in deeply Democratic New Jersey? Or might Murphy appoint his wife, first lady Tammy Murphy, who had launched a campaign for Menendez’s seat but dropped out after it became clear she faced a contentious battle against Kim?

Choosing his wife could be a political “non-starter,” said Micah Rasmussen, director of the Rebovich Institute for New Jersey Politics at Rider University.

Curtis Bashaw, the Republican candidate for the seat, already linked Tuesday’s corruption verdict to “the Democratic machine.” And Murphy said shortly after the Menendez indictment was unsealed last year and before her short-lived Senate candidacy that he didn’t see a scenario where he would appoint her to the seat.

What if there’s no vacancy?

The state Democratic Party abandoned Menendez after the indictment was unsealed last September, and he opted not to run in the primary as a Democrat. Republicans haven’t won a Senate seat in more than five decades in New Jersey, and Democrats have expressed confidence in Kim.

Still, it’s unclear how Menendez’s candidacy could affect the race if he stays in it.

He could still run for reelection and hold onto his seat, even if he’s facing or serving prison time, according to the National Constitution Center, a private nonprofit that focuses on constitutional education.