President Trump’s “not guilty” plea at a Miami courthouse on Tuesday is, for now, the latest word in the Mar-a-Lago documents case, but for Special Counsel Jack Smith, it merely signals a change in portfolios. The January 6 investigation looms, and with it the prospect of yet more, and potentially more serious, criminal charges.  

Mr. Smith, fresh off his face-to-face confrontation with the former president in that federal courtroom in the Sunshine State, is assigned by Attorney General Garland with investigating not only the documents stashed at Palm Beach — allegedly, among other places, in a bathroom — but also the events of January 6, 2021. 

General Garland authorized Mr. Smith “to conduct the ongoing investigation into whether any person or entity violated the law in connection with efforts to interfere with the lawful transfer of power following the 2020 presidential election.” Also looking into that in Georgia is a district attorney at Atlanta, Fani Willis, who’s widely expected to bring state charges against Mr. Trump in August or September.

Mr. Smith’s eyes appear trained at Nevada, for now. The chairman of the Nevada Republican Party, Michael Macdonald, was, along with the vice chairman of that group, Jim DeGraffenreid, spotted inside the Prettyman Federal Courthouse at downtown Washington, D.C., where the grand jury mulling charges with respect to January 6 meets.

Mr. McDonald led the Silver State’s effort to convene an alternative set of electors after the 2020 election that would deliver the state’s six Electoral College votes to Mr. Trump rather than President Biden. CBS News reported that the effort led to the FBI confiscating his cellphone.

In pushing his alternative slate of electors, Mr. McDonald explained that the “people of Nevada did not have a fair election due to the irregularities and fraud seen throughout the state.” He added: “With ongoing challenges and evidence left to be meaningfully investigated, we must submit our electoral votes for the rightful victors and allow Congress to make a determination.”

Mr. McDonald also testified before the January 6 committee on Capitol Hill, where he invoked his Fifth Amendment right against self-incrimination more than 200 times. NBC News reports that when asked his feelings on appearing before the grand jury on the same day as Mr. Trump appeared in federal court, Mr. McDonald responded that the activity was “not on my bucket list.”

President Biden beat Mr. Trump by 33,596 votes in Nevada, yet Mr. McDonald held a press conference where he “certified” Mr. Trump as the winner of his state’s electors. This effort was theoretically and practically developed by one of Mr. Trump’s attorneys, John Eastman, in a notorious series of documents known as the “Eastman memos.”

By summoning Messrs. McDonald and DeGraffenreid, Mr. Smith appears to be developing a case that the plan to substitute Nevada electors loyal to Mr. Trump for those committed to Mr. Biden was criminal. The plan would have depended on Vice President Pence going along. 

On January 6, though, Mr. Pence, cleaving to the Constitution, defied Mr. Trump’s demands and refused to block certification of the duly authenticated electors. Mr. Pence testified before the grand jury in April. 

One clue to the fate of the Nevadans could be discerned in Georgia, where all 16 people who signed an “unofficial electoral certificate” and offered themselves as replacement electors have been notified by Ms. Willis, the Fulton County D.A., that they are targets in her criminal probe. Eight of those electors have accepted immunity deals from the government, suggesting that they are cooperating.

Then there is Arizona. The former speaker of the Arizona house, Rusty Bowers, told the January 6 committee that, in a phone call, Mr. Trump attempted to cajole him to facilitate an alternative elector scheme in his state, as well. He replied to the president: “You are asking me to do something against my oath, and I will not break my oath.”

Last month, NBC News reports, Mr. Smith subpoenaed Mr. Trump’s sometime campaign manager and senior strategist, Steven Bannon, also in connection with January 6. Bannon is already facing convictions for criminal contempt of Congress for not appearing before the January 6 committee and was sentenced to four months in prison. He has appealed.