After months of wrangling, Virginia “Ginni” Thomas, the wife of US supreme court justice Clarence Thomas, has agreed to sit for an interview with the January 6 committee – thus avoiding a subpoena, at least for now.

This development could open a vital inquiry into Thomas’s alleged role in seeking to thwart a peaceful transition of presidential power to Joe Biden. Just as importantly, this news renews attention on the question of whether Ginni Thomas’s radical rightwing activism influenced her husband, who weighed in on numerous 2020 election-related cases despite his conflicts of interest.

So far, congressional Democrats have sat on their hands on this issue, presumably in deference to the supreme court. But with the rightwing court taking an axe to constitutional precedent and public opinion, an investigation into the Thomases might be the only way to course-correct what’s happening to the US constitution.

We know that Ginni Thomas texted Mark Meadows, the former White House chief of staff, between November 2020 and January 2021 urging measures to undermine Biden’s win and keep Trump in power. After Congress certified the election for Biden, she criticized former vice-president Mike Pence in a message to Meadows for refusing to disrupt the counting of electoral college votes, writing, “We are living through what feels like the end of America.”

The messages contain sly references to a “best friend”, which Ginni and Clarence Thomas have been known to call each other. In a viral Facebook post on 6 January 2020, now removed, she wrote, “LOVE MAGA people!!!!” Thomas attended the Capitol rally that day, though she has said she left before Trump’s speech at noon.

We also now know that Thomas emailed Arizona lawmakers in November and December of 2020, pushing them to devise a slate of presidential electors in defiance of Arizona voters’ choice for Biden. In an email in November, she urged Arizona legislators to “stand strong in the face of political and media pressure”, claiming (wrongly) that the choice of electors was “yours and yours alone”.

On 13 December, the day before the electors cast their votes for Biden, she circulated a second email stating: “Before you choose your state’s electors … consider what will happen to the nation we all love if you don’t stand up and lead,” and linking to a video of a man asking lawmakers not to “give in to cowardice”. On 14 December , a group of fake Trump electors met in Arizona to sign a document falsely declaring themselves the “duly elected and qualified electors” for the state.

Thomas allegedly waged a similar pressure campaign in Wisconsin. “Please stand strong in the face of media and political pressure,” she emailed two Republican lawmakers on 9 November, shortly after news outlets called the election for Biden. “Please reflect on the awesome authority granted to you by our constitution. And then please take action to ensure that a clean slate of electors is chosen for our state.”

Earlier this year, the New Yorker detailed Ginni Thomas’s deep connections to multiple rightwing groups that seek to influence the supreme court. Thomas, herself a lawyer who runs a small lobbying firm, Liberty Consulting, is on record as declaring America to be in danger due to a “deep state” and a “fascist left” peopled by “transexual fascists”. She posted about Trump’s loss on a private listserv, Thomas Clerk World, which includes approximately 120 former Clarence Thomas clerks. Artemus Ward, a political scientist at Northern Illinois University, has called the group “an elite rightwing commando movement”.

Thomas is also a director of CNP Action, a dark-money group that the New Yorker described as “connect[ing] wealthy donors with some of the most radical rightwing figures in America”, and on the advisory board of Turning Point USA, a conservative non-profit that sent busloads of protesters to the Capitol on January 6. And in 2019, she announced her partnership in Crowdsourcers, along with James O’Keefe, the founder of Project Veritas, an outfit known for producing embarrassing videos of progressives.

In 2020, Project Veritas petitioned the US supreme court to halt Massachusetts from enforcing a state law banning the secret taping of public officials. Another Crowdsourcers partner was Cleta Mitchell, a lawyer who played a central role helping Trump in his failed efforts to overturn the 2020 election results, and now faces ethics charges. Mitchell was on the 2 January 2021 phone call in which Trump cajoled the Georgia secretary of state, Brad Raffensperger, to “find” 11,780 votes to swing the state to Trump. That effort is being criminally investigated by a grand jury in Georgia.

According to the New York Times, the January 6 committee is most interested in asking Thomas about her communications with John Eastman, a conservative lawyer who infamously penned a six-step scheme for Pence to block or delay the counting of electoral college votes. According to the committee’s leaders, Eastman also “worked to develop alternative slates of electors to stop the electoral count”.

In a March opinion in Eastman v Thompson, a federal judge in California rejected Eastman’s attempt to keep his emails from the committee, identifying Eastman as probably having collaborated with Trump in multiple federal crimes, writing: “Based on the evidence … it is more likely than not that President Trump corruptly attempted to obstruct the Joint Session of Congress on January 6, 2021.”

The Thomases’ conflicts of interest have prompted calls for a supreme court code of conduct, which would require justices to recuse themselves from cases that might otherwise give rise to even an appearance of partiality. But it is not at all clear that Ginni Thomas is beyond the sights of criminal liability, either.

Of course, that sort of action would have to come through the justice department. Congress’s power is confined to making legislative changes. But the attorney general, Merrick Garland, has been resolute in his public commitment to enforce relevant federal laws, reiterating recently that “Rule of Law means that the law treats each of us alike: there is not one rule for friends, another for foes; one rule for the powerful, another for the powerless.” Ginni Thomas should be concerned.

For his part, Clarence Thomas was the only dissenting vote in a January 2021 ruling on an emergency application from Trump asking the supreme court to block the release of White House records to the January 6 Committee regarding the attack on the Capitol – records that in theory could have included messages between his wife and Meadows. He gave no reasons for his dissent.

Thomas also dissented, along with Justice Samuel Alito, from the court’s refusal to entertain a lawsuit by Texas asking that it toss out the election results in four other states – a legal “claim” that, to date, does not even exist as a matter of federal law.

Perhaps most disturbing is the court’s agreement to hear Moore v Harper this term, a case that strikes at the heart of the January 6 committee’s work. It raises a novel constitutional argument which Trump lost repeatedly in 2020: that the constitution lodges power over elections exclusively in state legislatures. If the court rules that legislatures have full power and control, it could cement unfairness in the electoral system as a matter of constitutional law, as many states are already gerrymandered to lock in power for one political party, mostly Republican.

Although Congress could legislatively add seats to the supreme court or impeach a justice, with evidence, to stave off further encroachments on individual rights and federal authority by this court, both measures would require a level of bipartisan support that is difficult to imagine.

Yet it’s impossible to predict where the further unraveling of the Ginni Thomas conflicts might lead – and whether those facts could produce another unprecedented fissure in our system of government. For now, Congress must, at the very least, peer behind the Thomases’ curtain.

• Kimberly Wehle is a law professor at American University and a legal analyst for ABC News. Her latest book is How to Think Like a Lawyer and Why