Ginni Thomas, the wife of the US supreme court justice Clarence Thomas, lobbied lawmakers in Wisconsin as well as Arizona in November 2020, seeking to overturn Joe Biden’s victories over Donald Trump in both swing states.

Thomas emailed lawmakers in support of Trump’s lie that Biden won thanks to electoral fraud.

The Washington Post reported Thomas’s efforts in Arizona earlier this summer. On Thursday it detailed her efforts in Wisconsin, citing emails obtained under public-records law.

Thomas emailed a Wisconsin state senator and a state representative, both Republican, on 9 November, two days after the election was called for Biden.

The messages used the same text as those sent to Arizona officials and were also sent using a form-emailing platform.

The subject line read: “Please do your constitutional duty!”

The text said: “Please stand strong in the face of media and political pressure. 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.”

Ginni Thomas did not comment to the Post. Nor did a supreme court spokesperson.

Citizens for Responsibility and Ethics in Washington, a watchdog group, said: “Ginni Thomas tried to overthrow the government. Clarence Thomas gets to rule on that attempt to overthrow the government. See the problem?”

After the deadly attack on the Capitol on 6 January 2021 by supporters Trump told to “fight like hell” to overturn his defeat, Clarence Thomas was the only justice to say Trump should not have to give White House records to the investigating House committee.

Ginni Thomas is now known to have been in touch with Mark Meadows, the White House chief of staff, and John Eastman, a law professor who claimed the vice-president, Mike Pence, could stop certification on January 6, about attempts to overturn the election.

The House January 6 committee asked Thomas to voluntarily sit for an interview and provide documentation. Her lawyer, the Post said, told the committee she was willing but he did not think she had to.

In July, Liz Cheney, the committee vice-chair, told CNN: “The committee is engaged with counsel. We certainly hope that [Thomas] will agree to come in voluntarily but the committee is fully prepared to contemplate a subpoena if she does not.”

No subpoena has been issued.

Cheney is a stringent conservative but last month she lost her Republican primary in Wyoming, over her opposition to Trump.

She has become popular with some on the left but others have grown frustrated, particularly over the lack of an attempt to compel Ginni Thomas to testify.

On Thursday, Elie Mystal, justice correspondent for the Nation, tweeted: “Answer the question ‘Why wasn’t Ginni Thomas subpoenaed by the January 6 committee?’ before you ask me to roll with Liz Cheney.”

One of the Wisconsin lawmakers who Thomas contacted, the state senator Kathy Bernier, spoke to the Washington Post.

She said: “As we went through the process and the legal challenges were made and discounted by the judicial system, there was nothing proven as far as actual voter fraud.”

Bernier also said she did not link Ginni Thomas’s actions to her husband’s position.

“I was married for 20 years,” she said. “I took on some identity of my husband, but I had my own mind. Just because you’re married to someone doesn’t mean that you’re a clone.”