Fulton County District Attorney Fani Willis will lay out the first details of her sprawling anti-racketeering case against former President Donald Trump, his White House chief of staff Mark Meadows and 17 other co-defendants at a federal court hearing on Monday.

This will be the first time that substantive arguments will be made in court about the four criminal cases brought against Trump this year.

The subject of the hearing is Meadows' motion to move his case to federal court and possibly have it thrown out, but it's much more than that -- it could end up acting as a mini-trial that determines the future of Fulton County's case against the former president.

Willis is expected to preview the case that she is planning to bring against the 19 co-defendants, getting on the public record some of her evidence and legal arguments for why Trump and his allies broke the law when pressuring Georgia election officials to meddle with the 2020 results.

Georgia Secretary of State Brad Raffensperger, who received the January 2021 call from Trump to "find" the votes that would reverse his loss, has been subpoenaed to testify, along with an investigator in his office and two other lawyers who were present on the call.

Here's what to watch for:

'Opening salvo' in bids to move to federal court

Meadows is one of several defendants who have filed to move their cases from Georgia state court to federal court, and Trump is expected to file a similar motion.

Several defendants who have filed similar removal notices, including ex-Georgia Republican Party chair David Shafer and Cathy Latham, who served as a fake elector, have argued they were acting at Trump's direction.

Meadows is arguing that the charges against him in Georgia should be dismissed under a federal immunity claim extended, in certain contexts, to individuals who are prosecuted or sued for alleged conduct that was done on behalf of the US government or was tied to their federal position.

While he may still face an uphill battle to move his case, Meadows is "uniquely situated" in Willis' case, said Steve Vladeck, a CNN analyst and professor at the University of Texas School of Law.

"Folks should be wary of this being a bellwether," Vladeck said, describing the dispute instead as an "opening salvo in what is going to be a long and complicated series of procedural fights."

If US District Judge Steve Jones grants Meadows' or another defendant's request to move the prosecution to federal court, it does not ultimately doom Willis' case.

For one, it is not clear whether Meadows' co-defendants would join him in the federal forum, and even if the judge accepts Meadows' claim that his case should play out in federal court, it does not mean that Jones will buy Meadows' arguments that the charges against him should be dismissed.

For instance, in Trump's New York case, in which he was charged by the Manhattan district attorney with 34 counts of falsifying business records, a federal judge rejected the former president's bid to move the case to federal court.

What the judge will be considering

US law allows defendants in state civil suits or criminal cases to seek to move those proceedings to federal court if those defendants face charges based on conduct they carried out "under color" of the federal government.

While such proceedings are not uncommon in civil lawsuits against current and former federal officials, they are extremely rare in criminal cases, legal experts told CNN, meaning Jones will be navigating in uncertain legal territory.

"This is just that rare case where there is just not a lot of law," Vladeck said.

Meadows is arguing that under the Constitution's Supremacy Clause, the federal court should dismiss the charges against him, because the conduct underlying the charges was conducted as part of his duties as a close White House adviser to Trump.

"If Mr. Meadows had absented himself from Oval Office meetings or refused to arrange meetings or calls between the President and governmental leaders, that would have affected his ability to provide the close and confidential advice that a Chief of Staff is supposed to provide," Meadows' lawyers wrote in a court filing.

Beyond Meadows' participation on the Raffensperger call, Willis has also highlighted as alleged acts in the racketeering conspiracy his surprise visit to an Atlanta election audit and a request Meadows and Trump are said to have made to a White House official to compile a memo on how to disrupt the January 6, 2021, election certification vote in Congress.

"In order to prevail, Meadows has to convince the court that when he was banging on the audit door he wasn't representing the private interests of Donald Trump," said Lee Kovarsky, a University of Texas law professor and expert in the removal statute.

Willis, in her response to Meadows' filings, is leaning on a federal law known as the Hatch Act, which prohibits government officials from using their federal office to engage in political activity, including campaign-oriented conduct. She argues Meadows' involvement in the pressure campaign on Georgia election officials is clearly conduct he was not allowed to engage in as a federal officer, and therefore he is not entitled to the federal immunity defense.

The Hatch Act framing is a "nice way of illustrating that he was acting outside the scope of his official duties," Kovarsky said, adding that Willis will not have to prove that Meadows violated the federal statute to be successful in the argument.

Willis' filings in the dispute also appear to be a shot across the bow at Trump and any attempt he could make with similar claims.

"An evaluation of the actions named in the indictment makes clear that all of them were intended to 'interfere with or affect' the presidential election in Georgia and elsewhere in order to somehow transform Mr. Trump from an unsuccessful candidate into a successful one," the district attorney's office said. "The activities are precisely the type which other courts have already determined to be 'unofficial' and therefore beyond the color of the defendant's office."

Key witnesses potentially taking the stand

Jones, a Barack Obama appointee, has shown that he would like to avoid a circus while also not giving short shrift to Meadows' arguments, Vladeck said. The orders the judge has already issued have hewed tightly to the relevant statutes and case law, and he has moved the proceedings along efficiently.

The judge is "by the book, which includes quickly and quietly," Vladeck said.

Still, the hearing could feature some revelatory moments, as Willis appears to be preparing to put on the stand several witnesses to the pressure campaign Trump and Meadows are accused of applying to Georgia election officials.

In addition to Raffensperger, Willis subpoenaed Frances Watson, who was chief investigator in the Georgia secretary of state's office. According to the grand jury indictment, Meadows arranged a call between Trump and Watson, and texted Watson himself to offer Trump campaign funding toward speeding up a ballot review in Fulton County.

Willis also subpoenaed two lawyers who were on the Trump-Raffensperger phone call on Trump's behalf: Kurt Hilbert and Alex Kaufman.

"The central question is: Were Meadows and Trump acting in the context of ... their federal positions, or were they just candidates for office or campaign staff acting in the state of Georgia?" said Elliot Williams, a CNN legal analyst and former Justice Department official. "Raffensperger will come to testify as to, 'Maybe I actually think these guys were acting on behalf of the campaign, not the presidency.'"