John Eastman, a lawyer who advised Donald J. Trump’s 2020 election campaign, was arraigned in Phoenix on Friday on state criminal charges that he helped try to keep Mr. Trump in power after he lost the last presidential election.
Mr. Eastman is the first of 18 defendants to come before a judge in the Arizona case, which was brought by Kris Mayes, the state attorney general. Mr. Eastman faces charges of fraud, forgery and conspiracy.
Several other prominent defendants in the case are scheduled to be arraigned next week, including Boris Epshteyn, who remains one of Mr. Trump’s top legal advisers, and Mark Meadows, a former White House chief of staff.
Rudolph W. Giuliani, formerly Mr. Trump’s personal lawyer, has also been charged in the case.
The arraignment of Mr. Eastman took place at a large courthouse complex in Phoenix Friday morning. Mr. Eastman appeared briefly before a judge and pleaded not guilty.
“I’m confident that with the laws faithfully applied, I will be fully exonerated,” he said afterward.
When she filed the charges last month, Ms. Mayes, a Democrat, said: “I will not allow American democracy to be undermined. It’s too important.”
Mr. Eastman helped devise a plan to put forward fake electors for Mr. Trump in Arizona and six other swing states that he lost, as part of an effort to have Congress block or delay certification of Joseph R. Biden’s victory on Jan. 6, 2021. Mr. Eastman also faces racketeering and other charges in Georgia related to a similar election interference effort there.
He has been temporarily barred from practicing law in California and in Washington, D.C. A California judge recommended in March that he be disbarred.
Mr. Eastman has continued to say that the 2020 election was stolen, though no evidence has ever emerged to support that assertion. He has insisted that he did nothing wrong and was merely providing legal advice to the Trump campaign.
The Arizona indictment says that Mr. Eastman and the other defendants made a series of efforts to overturn Arizona’s election results. They are accused of putting pressure on “officials responsible for certifying election results to encourage them to change the election results,” among them the governor, members of the State Legislature and the board of supervisors in Maricopa, the state’s most populous county.
When it became clear that those efforts would not bear fruit, the indictment says, a group of fake electors met at the headquarters of the Arizona Republican Party. They signed a document purporting to certify Arizona’s electoral votes for Mr. Trump, which was then submitted to Congress.
“I think the evidence will show that my client did not have any communication or any contact with any of the Arizona electors,” Ashley D. Adams, a lawyer for Mr. Eastman, said in an interview this week. Ms. Adams, a former federal prosecutor in Phoenix, said that “it’s going to be tough for the state to prove a conspiracy.”
Harvey Silverglate, another lawyer representing Mr. Eastman, said that the prosecution is “trying to overwhelm these defendants in order to force guilty pleas.”
“Not only do they face endless amounts of trial time, but it’s enormously expensive to defend these cases,” Mr. Silverglate said. “John Eastman spends about 80 percent of his time going around the country fund-raising for his legal defense.”
A number of lawyers who worked in the White House during the Trump administration expressed contempt for Mr. Eastman in testimony to the House committee that investigated the Jan. 6, 2021 attack on the Capitol, portraying him as an academic with little grasp of the real world.
Greg Jacob, who served as legal counsel to former Vice President Mike Pence, characterized Mr. Eastman’s legal advice as “gravely, gravely irresponsible,” calling him the “serpent in the ear” of Mr. Trump. Eric Herschmann, a Trump White House lawyer, recounted “chewing out” Mr. Eastman. Pat A. Cipollone, a former chief White House counsel, is described in testimony calling Mr. Eastman’s ideas “nutty.”
Mr. Eastman, though, was part of a faction of legal advisers who eventually prevailed in persuading Mr. Trump to take extreme measures to try to stop the transfer of power to Mr. Biden, including pressuring Mr. Pence unsuccessfully to refuse to certify the election results on Jan. 6.
Arizona is one of four states where prosecutors have brought criminal charges related to the Trump campaign’s efforts to reverse the results of the 2020 election. The Georgia case against Mr. Trump and many of his allies, including Mr. Eastman, was brought last year by Fani T. Willis, the district attorney of Fulton County, Ga. It is not expected to go to trial until next year.
Lawyers for Mr. Trump have been trying to get Ms. Willis disqualified from the case because of a romantic relationship she had with the lawyer she hired to manage the prosecution. On Thursday, they formally appealed a ruling thwarting their effort. Legal wrangling over the matter is one factor delaying the Georgia case.
Another prosecution has been brought in Nevada by the state attorney general, Aaron Ford, against six people who signed up to be fake pro-Trump electors in 2020. That case, too, is expected to go to trial next year.
Earlier this week in a Las Vegas courtroom, Judge Mary Kay Holthus asked prosecutors to submit a brief explaining the illegal acts that they allege took place in Clark County, which encompasses Las Vegas.
Filings from the defendants have pointed out that the fake Trump electors met in Carson City, the state capital, which is in a different county.
“What exactly occurred here to give us jurisdiction?” the judge said during the hearing, adding, “I mean, let’s face it, the majority of this happened elsewhere, the way I read it.”
Dana Nessel, the attorney general of Michigan, has brought criminal charges against fake electors in that state. Pretrial hearings in the case have been underway for several months.
In Phoenix, more arraignments are expected on Tuesday.
