Illinois Sen. Dick Durbin, the chair of the Senate Judiciary committee, called for Supreme Court Justice Clarence Thomas to recuse himself from weighing in on whether former President Donald Trump can be removed from states’ 2024 ballots for his role in the Jan. 6, 2021, attack on the U.S. Capitol.

The nation’s highest court is expected to hear arguments on Thursday in the case, which centers on the Colorado Supreme Court’s decision to remove the GOP frontrunner from their state’s primary ballot. The state court ruled Trump ineligible based on the 14th Amendment of the U.S. Constitution’s insurrection clause, a Civil War-era provision that bars those who took an oath of office as a U.S. official from federal office for participating in a rebellion or insurrection.

Durbin argued the involvement of Thomas’ wife, conservative activist Ginni Thomas, in the effort to overturn Trump’s 2020 presidential election loss creates a conflict of interest for the justice.

“I’m calling for Justice Clarence Thomas to recuse himself in the 14th Amendment case determining if Donald Trump is ineligible for the 2024 ballot,” Durbin posted on X, formerly known as Twitter, on Wednesday. “Given questions surrounding his wife’s involvement, Justice Thomas should recuse himself so there’s no question of bias.”

Challenges to Trump’s ballot eligibility have been filed in at least 35 states, with 17 challenges dismissed or rejected and 16 left unresolved, according to a New York Times analysis. In addition to Colorado, Maine’s Democratic secretary of state has also barred the former president from the primary ballot.

Since the attack on the U.S. Capitol by Trump’s supporters, Clarence Thomas has recused himself from a single case: an appeal by pro-Trump attorney John Eastman involving emails obtained by the congressional select committee investigating the Capitol attack. Thomas was mentioned in those emails by another attorney, Kenneth Chesebro, as “our best shot” at delaying the certification of the vote in disputed states ahead of Congress’s certification of the Electoral College vote on Jan. 6, 2021. Clarence Thomas did not explain the reason for his recusal.

Otherwise, he has declined to recuse himself for previous election interference cases both before and after his wife’s role was made public, including one ruling that allowed the House committee investigating the Jan. 6 attack access to records from the Trump White House. He was the only one of the nine justices to dissent in the ruling. There was no explanation, as is customary with the high court.

Eastman, who once clerked for Thomas as well, was in contact with Ginni Thomas in the months leading up to the Electoral College certification, by the attorney’s own admission. Though he denied discussing “any matters pending or likely to come before the Court” with either Ginni or Clarence Thomas,” Eastman wrote last year he did exchange emails with Ginni Thomas, including one where she invited him to give an update about “election litigation” to a group of “grassroots state leaders” she was associated with.

In that Dec. 4, 2020, email, which Eastman published himself, Ginni Thomas does refer to herself as “on sabbatical until this election stuff is resolved” but praised Eastman as “doing an unbelievably great job” and was attempting to coordinate a Zoom call with the group she was affiliated with. In one court filing, House Jan. 6 panel investigators refer to their efforts obtaining documents related to a Dec. 8, 2020, meeting that Eastman spoke at after being invited by “the group’s high-profile leader.”

“Based on the agenda, Dr. Eastman discussed ‘State legislative actions that can reverse the media-called election for Joe Biden,” the committee’s attorneys wrote in the June 7, 2022, filing. “Another speaker gave an ‘update on [state] legislature actions regarding electoral votes.’”

Ginni Thomas has been an active figure in conservative politics for decades and was in frequent communication with then-White House Chief of Staff Mark Meadows in the lead up to Jan. 6, urging him to push election fraud claims and keep now-President Joe Biden from assuming the presidency, according to the Washington Post and CBS News.

In September 2022, the chair of the House Jan. 6 select committee, Mississippi Rep. Bennie Thompson, said that Ginni Thomas was still promoting false claims about the 2020 election during a four hour interview with investigators.

Clarence Thomas has also recently come under months of scrutiny for his relationships with powerful conservative movement figures and Republican donors.

Ginni Thomas has not been charged with a crime or publicly identified as the subject of any investigation. But Trump, Eastman, Chesebro and 16 others were charged in Georgia with racketeering and other felonies for allegedly participating in an illegal scheme to overturn the 2020 election in the key swing state.

Chesebro, attorney Sidney Powell and a Scott Hall, a Georgia bail bondsman, all pleaded guilty last fall.

Trump is also facing federal charges in Washington for his efforts to undo his loss. All together, the first former president to ever face criminal charges is being prosecuted for 91 felonies, including another federal case centered on his handling of classified documents in Florida and a state case in New York examining alleged business fraud.

The Supreme Court could also take up Trump’s claim that presidents should have immunity from prosecution after a three-judge federal appeals panel unanimously rejected his claims on Tuesday.

The Supreme Court currently has a 6-3 conservative majority, including three judges appointed by Trump.

Spectrum News’ Justin Tasolides contributed to this report.