Originally Published: 05 OCT 21 10:06 ET

Updated: 05 OCT 21 12:12 ET

By Devan Cole, CNN

(CNN) -- A bipartisan group of former public officials and lawyers are urging the California bar association to investigate a conservative lawyer who reportedly tried to convince then-Vice President Mike Pence that he could overturn the election results on January 6.

In a letter sent Monday by more than two dozen people -- including a former president of the State Bar of California, two former federal judges and a host of other former state officials and experts from across the US -- to George Cardona, who oversees disciplinary matters for the SBC, the group said that "serious evidence of professional misconduct" by pro-Trump attorney John Eastman should be investigated.

"The available evidence supports a strong case that the State Bar should investigate whether, in the course of representing Mr. Trump, Mr. Eastman violated his ethical obligations as an attorney by filing frivolous claims, making false statements, and engaging in deceptive conduct," the letter states.

As CNN previously reported, Eastman's efforts while working with then-President Donald Trump's legal team were detailed in a new book from Washington Post journalists Bob Woodward and Robert Costa. The scheme he had put forward was outlined in a two-page memo obtained by the journalists and which was subsequently obtained by CNN. The memo, which had not previously been made public, provides detail showing how Trump and his team tried to persuade Pence to subvert the Constitution and throw out the election results as Congress worked to certify the Electoral College votes.

The Eastman memo laid out a six-step plan for Pence to overturn the election for Trump, which included throwing out the results in seven states because they allegedly had competing electors. In fact, no state had actually put forward an alternate slate of electors -- there were merely Trump allies claiming without any authority to be electors.

The letter sent Monday to Cardona points to Eastman's memo, in addition to other actions taken by him, with the signatories saying that the document's "claim was based on nothing more than the notion that the legitimacy of the election continued to be 'disputed' in some unexplained fashion."

"That conclusion was thoroughly wrong -- and Mr. Eastman knew it or was willfully blind," they wrote.

CNN has reached out to Eastman for comment.

The group also makes reference to other disciplinary actions taken against pro-Trump attorneys who helped the former President's legal efforts to overturn the election.

"Though much of Mr. Eastman's conduct involved speech on political subjects, it is not protected by the First Amendment. As the discipline and sanctions already meted out to other Trump attorneys demonstrate, a lawyer representing a politician and dealing directly with courts and third persons is not free to ignore reality. Instead, a lawyer must avoid speech that is intentionally false or deceptive," the letter states in part.

The letter was written on behalf of the States United Democracy Center, a nonpartisan organization whose work includes "helping to ensure that democracy violators are held accountable," according to the complaint.

Norm Eisen, the organization's executive chair and one of the letter's signatories, declined to say Monday whether the group is hoping the California bar suspends Eastman's law license, as the New York bar and Washington, DC, bar did earlier this year to Rudy Giuliani, another pro-Trump attorney.

"That determination ... is for the California state bar," Eisen, who served as former President Barack Obama's ethics czar and ambassador to the Czech Republic, told CNN in an interview. "The consequences of the assault by President Trump and his enablers on our democracy are reverberating to the present day."

"And Mr. Eastman played a prominent role in that," he added. "And we think that his reported statements of fact and law alike that were facilitated by his law license and his standing as an attorney should be very closely reviewed by the bar."

Eisen also said the bipartisan nature of the letter demonstrates the seriousness of the matter.

"We do have an extraordinary bipartisan array because the concerns here transcend the usual partisanship," he said. "This is as serious a basis as you can get to request an investigation."