“I think that people thought that we came into this as some kind of game,” the veteran Democratic prosecutor told NBC News on Wednesday. “This is not a game at all. What I am doing is very serious.”

The maneuvering represents a major escalation in the probe, which was launched in February 2021 and is taking place at the same time a Congressional committee is examining Trump’s role in the Jan. 6 attack on the U.S. Capitol.

Until last week, Georgia prosecutors largely focused on calling state and local witnesses to testify before the 23-person grand jury, which has met in secret since May and is tasked with writing a report that will recommend whether Willis should press charges against Trump or anyone else.

An indictment of a former president would be unprecedented in U.S. history.

Among those who have testified so far in the Fulton County probe are Secretary of State Brad Raffensperger and his top aides, Attorney General Chris Carr, several Democratic legislators and senior elections officials from Cobb and DeKalb counties. Gov. Brian Kemp is expected to deliver a sworn recorded statement to the jury later this month.

Danny Porter, the longtime former DA of neighboring Gwinnett County, said it will be much more challenging to secure testimony from Trump’s advisers.

“I think the circus has just begun,” said Porter, a Republican. “Once they start hitting these people — Giuliani, Eastman, Graham — you’re going to see a flurry of legal filings to try and prevent them from having to appear in front of the grand jury.”

Out-of-state challenges

Indeed, attorneys for Graham have already promised to challenge his subpoena. Lawyers Bart Daniel and Matt Austin indicated the Republican could cite the “Speech and Debate” clause of the U.S. Constitution, which shields members of Congress from being questioned in court about their legislative activities and the motivations behind them.

Graham placed two phone calls to the Secretary of State’s office in late 2020 to inquire about reexamining absentee ballots “in order to explore the possibility of a more favorable outcome” for Trump, his subpoena alleges.

Daniel and Austin said that Graham was “well within his rights” as the chairman of the Senate Judiciary Committee at the time to “discuss with state officials the processes and procedures around administering elections.”

Out-of-state witnesses who object to subpoenas are entitled to a hearing before a superior court judge in their home states, during which they can argue why they aren’t “necessary and material” to the investigation, or why testifying would be an undue hardship. Fulton prosecutors would also appear to defend the summons.

Porter said that such hearings will largely be “pro-forma” since the Fulton subpoenas lay out exactly why prosecutors see each witness’s testimony as critical to the probe. He said home state judges can grant a bond directing the witnesses to appear in court in Atlanta on a certain date or hold them in custody until they can be picked up by Fulton authorities.

“That’s the big difference between a regular subpoena and a material witness subpoena. There’s some muscle behind a (material witness) subpoena,” said Pete Skandalakis, executive director of the Prosecuting Attorneys’ Council of Georgia. “You’re just not going to be able to not show up.”

It is when the witnesses arrive in Fulton that they would likely make their arguments about legislative immunity or attorney-client privilege, according to Skandalakis and Porter. Six of the people who were sent material witness subpoenas on Tuesday are lawyers connected to the Trump campaign and could try and cite attorney-client privilege.

Caren Morrison, an associate professor of law at Georgia State University and a former federal prosecutor, noted that attorney-client privilege isn’t necessarily an impenetrable defense.

“You can have an attorney-client relationship but if the object of your discussion was to commit a crime or perpetrate a fraud then the privilege doesn’t apply,” she said, describing what’s known as the “crime-fraud exception.”

A federal judge in California ruled in March that Eastman was required to turn over emails to Congress’ Jan. 6 committee because they contained evidence of a potential crime and thus were subject to the exception.

To compel the testimony of Trump’s attorneys, prosecutors may argue that the campaign unlawfully tried to override the will of voters by pushing for the decertification of election results in swing states like Georgia. That’s along the lines of what the DA’s office said recently as it’s fought for the testimony of multiple state Republican legislators who were citing legislative immunity.

Even if prosecutors are successfully able to compel testimony from witnesses like Eastman, the grand jury may not get much out of them.

When Eastman was deposed by the Jan. 6 committee, he exercised his right against self-incrimination more than 100 times. It was later revealed that he and Giuliani were among the White House allies who allegedly sought pardons from Trump during his last days in office.

Prosecutors’ interests becoming clearer

The subpoenas, combined with a recent filing arguing for the testimony of those GOP legislators, have provided the clearest look yet at where the Fulton DA’s office is going with its criminal investigation.

Many of the subpoenaed witnesses fall into three categories: people who were on various phone calls that Trump or his allies placed to Georgians between Nov. 2020 and Jan. 2021; people involved in the effort to coordinate a slate of “alternative” Republican electors; and people who participated in a Dec. 3, 2020 Senate subcommittee hearing where Giuliani and others testified about what they saw as widespread fraud in Georgia’s elections.

Raffensperger, Kemp, Carr and Francis Watson, the former chief investigator for the Secretary of State’s office, were all summoned to testify before the special grand jury. All spoke with Trump over the phone after the elections. Raffensperger also received a call from Graham in Nov. 2020.

Cleta Mitchell, who worked with the Trump campaign after the election and was subpoenaed Tuesday, and Ryan Germany, the general counsel for the Secretary of State’s office who spoke with the grand jury last month, were parties on the infamous Jan. 2, 2021 call Trump placed to Raffensperger in which he asked for the secretary of state to “find” 11,780 votes.

Giuliani, Eastman and attorney Kenneth Chesebro, who were all subpoenaed on Tuesday, allegedly had major roles in the electors scheme.

Eastman also testified at the Senate subcommittee hearing with Giuliani, as did attorneys Jenna Ellis and Jacki Pick Deason, who were also subpoenaed this week. The grand jury has already interviewed multiple Democratic legislators about the hearing and sought testimony from former Sen. William Ligon, R-Brunswick about the matter, though a judge on Wednesday severely limited the ability of prosecutors to ask Ligon questions about his post-election actions because of legislative privilege.

Porter said that the latest batch of subpoenas suggest that prosecutors are trying to lock down criminal intent, a necessary component for proving that Trump or others broke the law.

“Based on what I know about the testimony and the witnesses that have already occurred, the basic groundwork has been laid about the existence of a possible crime. But you’ve always got to look at what was the intent of the alleged perpetrator,” he said. “I think the only way that you can get to that is the people who knew Trump best.”

Investigation Interests

Based on recent subpoenas requested by the Fulton special grand jury, prosecutors appear to be homing in on three sets of events that occurred after Georgia’s 2020 elections:

Phone calls

Then-President Donald Trump spoke on the phone with Gov. Brian Kemp, Secretary of State Brad Raffensperger, Attorney General Chris Carr and former elections investigator Frances Watson. All with the exception of Trump have been compelled to testify before the special grand jury, as has U.S. Sen. Lindsey Graham, who separately called Raffensperger and his aides.

“Alternative” Republican electors

Attorneys Rudy Giuliani, John Eastman and Kenneth Chesebro, all subpoenaed this week, allegedly had major roles in coordinating a slate of “alternative” GOP electors in swing states including Georgia.

The Giuliani hearing

Giuliani, Eastman and two other attorneys who spoke about widespread election fraud at a Dec. 3, 2020 subcommittee hearing in the Georgia Senate have all been been summoned to testify, as have several Democratic legislators who were there and the Republican senator who organized the event.