A few days before the 2020 election was slated to be certified by Congress, the lawyer Jenna Ellis sent President Donald J. Trump a memo suggesting a way he could stay in power by upending the normal course of American democracy.
In the memo, Ms. Ellis, who had little experience in constitutional law, offered Mr. Trump advice he was also getting from far more seasoned lawyers outside government: to press his vice president, Mike Pence, who would be overseeing the certification ceremony at the Capitol on Jan. 6, 2021, not to open any Electoral College votes from six key swing states that Mr. Trump had lost.
While Mr. Pence ultimately rejected Mr. Trump’s entreaties, state prosecutors in Georgia later accused Ms. Ellis of helping to develop a strategy for “disrupting and delaying” the election certification and with working closely with pro-Trump lawyers like Rudolph W. Giuliani as part of a sprawling racketeering case.
On Tuesday, Ms. Ellis pleaded guilty to some of those charges at a court proceeding in Georgia, in which she tearfully agreed to work with the Fulton County District Attorney’s Office as it continues to prosecute Mr. Trump, Mr. Giuliani and more than a dozen other people.
During her plea hearing, Ms. Ellis told the judge that she had relied on lawyers “with many more years of experience” than she had, a potentially ominous sign for Mr. Giuliani in particular.
A spokesman for Mr. Giuliani did not immediately respond to a request for comment.
With her guilty plea, Ms. Ellis became the fourth defendant — and the third lawyer — in the case to reach a cooperation deal with Fani T. Willis, the Fulton County district attorney. What began with a trickle last week, when two other pro-Trump lawyers — Sidney Powell and Kenneth Chesebro — pleaded guilty and agreed to turn state’s evidence, started to look a lot like a flood when Ms. Ellis appeared in court.
While a person familiar with Ms. Ellis’s thinking described her as being extremely angry at Mr. Giuliani, her cooperation could be perilous for Mr. Trump as well. Ms. Ellis was on board with Mr. Trump’s team up until the end of his term in office — and he has since refused to help her with her legal bills. And unlike a number of people swirling around the former president, she had a direct relationship to Mr. Trump and was in contact with him at various points while he was in the White House.
Indeed, if Ms. Ellis, Ms. Powell and Mr. Chesebro all end up taking the stand, they could paint a detailed collective portrait of Mr. Trump’s activities in the postelection period. Their accounts could include the thinking behind the frivolous lawsuits filed on his behalf challenging the results of the election and the role Mr. Trump played in a scheme to create false slates of electors claiming he had won states he did not.
They could touch upon a brazen plot, rejected by Mr. Trump, to use the military to seize the country’s voting machines. And they could detail his efforts to strong-arm Mr. Pence into unilaterally throwing him the election on Jan. 6 — an effort that prosecutors say played a part in exciting the mob that stormed the Capitol.
Steven H. Sadow, the lead lawyer representing Mr. Trump in the Georgia case, said the series of pleas shows “this so-called RICO case is nothing more than a bargaining chip” for the district attorney in charge of the prosecution, Fani T. Willis. He added that Ms. Ellis had pleaded guilty to a charge that was not part of the original indictment and that “doesn’t even mention President Trump.”
A former prosecutor from a mostly rural county north of Denver, Ms. Ellis initially caught Mr. Trump’s eye by appearing on Fox News, where she beat the drum for some of his political positions — his immigration policy, among them. Mr. Trump formally brought her on as a campaign adviser in November 2019.
The following year, she was among the people whom Mr. Trump often spoke with as Black Lives Matter protests erupted across the country, including in Washington. The local protests, some of which took place near the White House, enraged Mr. Trump and he looked for people to validate his desire to employ the force of the federal government to stop them.
After Mr. Trump lost the election, Ms. Ellis quickly signed on with a self-described “elite strike force,” a group of lawyers that included Ms. Powell and Mr. Giuliani and began to push the false narrative that the presidential race had been rigged.
In mid-November 2020, she appeared at a news conference in Washington where, as dark liquid dripped down Mr. Giuliani’s face, Ms. Powell laid out an outrageous conspiracy theory that a voting machine company called Dominion had used its election software to flip thousands of votes away from Mr. Trump to his opponent, Joseph R. Biden Jr.
As Ms. Powell and other lawyers began to file a flurry of lawsuits challenging the election results, Ms. Ellis embarked on a kind of a traveling roadshow, accompanying Mr. Giuliani to key swing states for informal hearings with state lawmakers where they presented claims that Mr. Trump had been cheated out of victory.
Over the span of about a week, in November and early December 2020, Ms. Ellis sat beside Mr. Giuliani at gatherings in Pennsylvania, Arizona, Michigan and Georgia. Their presence at these events, prosecutors say, was often coupled with direct appeals to state officials either to decertify the election results or to join in the so-called fake elector scheme.
Even after Mr. Trump left office in 2021, he urged Ms. Ellis to keep alive the notion that he could be restored to the presidency.
From Mar-a-Lago, his private club and residence in Florida, he encouraged various people — among them, conservative writers — to promote the idea that the efforts to overturn the results were not at an end and that there was still a possibility he could be returned to the White House.
When Ms. Ellis posted on X that such a thing was impossible, Mr. Trump told her that her reputation would be damaged, a statement she took as pressure to reverse what she had said, according to a person with direct knowledge of the discussion.
Mr. Trump, according to two people with direct knowledge of the discussion, conceded it was “almost impossible” but said that he wanted to keep the idea in circulation. It was an early sign of tension with the former president.
Ms. Ellis has already said that she knowingly misrepresented the facts in several of her public claims that voting fraud had led to Mr. Trump’s defeat. Those admissions came as part of a disciplinary procedure conducted this spring by Colorado state bar officials.