(The Hill) — Rep. Liz Cheney (R-Wyo.) said Sunday that the House committee investigating the Jan. 6 riot is “fully prepared to contemplate a subpoena” for Virginia “Ginni” Thomas, the wife of Supreme Court Justice Clarence Thomas, if she won’t testify before the committee voluntarily.

“The committee is engaged with her counsel. We certainly hope that she will agree to come in voluntarily but the committee is fully prepared to contemplate a subpoena if she does not,” Cheney told CNN “State of the Union” co-host Jake Tapper. “I hope it doesn’t get to that. I hope she will come in voluntarily.”

Thomas has been under scrutiny for her political affiliations and communications with the Trump administration about overturning election results.

She attended the pro-Trump “Stop the Steal” rally just before rioters stormed the Capitol, and she communicated with former White House Chief of Staff Mark Meadows and and Trump attorney John Eastman about overturning the 2020 presidential election results.

Cheney said Sunday that the committee has heard from “numbers of people who are similarly situated in terms of the discussions that she was having,” and stressed the importance of hearing Thomas’ testimony. 

Thomas reportedly said in early June that she was eager to appear before the panel, but her lawyer later said he didn’t see a need for her testimony.

Committee members hope to learn more about Ginni Thomas’ effort to keep Trump in office and the potential conflicts of interest for Clarence Thomas as a result on Jan. 6 cases that have come before the Supreme Court.

Lawmakers on the Jan. 6 committee also said they are deepening their inquiry after a series of eight hearings in June and July culminating in a prime-time session Thursday, with plans to interview additional witnesses and reconvening in September to resume laying out their findings to the public.

“We anticipate talking to additional members of the president’s Cabinet,” Cheney said. “We anticipate talking to additional members of his campaign. Certainly, we’re very focused as well on the Secret Service.”

Cheney did not identify the Trump administration officials who might come forward, but the committee has previously made clear its interest in speaking with those believed to have considered invoking a constitutional process in the 25th Amendment to remove Trump from office after the Jan. 6, 2021 riot, when hundreds of Trump’s supporters violently stormed the Capitol and interrupted the certification of Joe Biden’s election.

The committee has aired testimony from former Attorney General William Barr, who said he told Trump that widespread voter fraud claims had “zero basis.” In last week’s hearing, the committee played testimony from then-Labor Secretary Eugene Scalia, who said he urged Trump to call a Cabinet meeting to discuss an orderly transition of power.

Other Cabinet members have indicated they may have important details to share.

Betsy DeVos, the education secretary at the time, previously told USA Today that she raised with Vice President Mike Pence the question of whether the Cabinet should consider invoking the 25th Amendment, which would have required the vice president and the majority of the Cabinet to agree that the president could no longer fulfill his duties.

DeVos, in her resignation letter Jan. 7, 2021, blamed Trump for inciting the mob: “There is no mistaking the impact your rhetoric had on the situation, and it is the inflection point for me,” she wrote.

On the same day, Elaine Chao quit as transportation secretary. Chao, who is married to Senate GOP leader Mitch McConnell of Kentucky, said the attack had “has deeply troubled me in a way that I simply cannot set aside.”