President Donald Trump's lawyers are keenly focused on the special counsel Robert Mueller's case in Virginia against Paul Manafort, Trump's former campaign chairman.

Manafort's lawyers are arguing for the dismissal of the case.

One source with knowledge of the matter said Trump's legal team was "anxious to see that answer."

Legal experts say that if the case were dismissed, it would benefit Trump's legal team for two key reasons.

President Donald Trump's lawyers are anxiously awaiting the next development in the special counsel Robert Mueller's case in Virginia against Paul Manafort, Trump's former campaign chairman.

That development could play a significant role in what steps Trump's legal team takes next.

The Virginia indictment charges Manafort with financial crimes, including tax and bank fraud, related to his lobbying work for the Ukrainian government and pro-Russia interests in Ukraine.

Manafort's defense team is seeking the dismissal of the case, arguing that because its charges fall outside Mueller's core mandate — investigating whether the Trump campaign colluded with Russia to influence the outcome of the 2016 US election — he is not authorized to bring the case.

US District Court Judge T.S. Ellis III, who expressed deep skepticism about Mueller's case against Manafort in a hearing about Manafort's motion last week, seemed to indicate a level of openness to Manafort's defense. Ellis has asked to review an unredacted copy of a memo from August in which Deputy Attorney General Rod Rosenstein authorized Mueller to investigate Manafort's work in Ukraine.

Trump's legal team is "anxious to see that answer" of what Ellis decides when he reviews the memo, a source familiar with the Trump team's thought process told Business Insider.

Trump's legal team is in talks with Mueller about arranging an interview with the president. Though negotiations are ongoing, the source said Trump's lawyers could decide to "keep quiet for a while and just study" the Manafort case.

Trump was excited by Ellis' assertions last week

At one point during last week's hearing, Ellis suggested that the reason prosecutors were going after Manafort was to try to get him to flip on Trump.

"I don't see what relation this indictment has with what the special counsel is authorized to investigate," Ellis told prosecutors. "You don't really care about Mr. Manafort's bank fraud ... What you really care about is what information Mr. Manafort could give you that would reflect on Mr. Trump or lead to his prosecution or impeachment."

Donald Trump. Chip Somodevilla/Getty Images

Ellis later quipped: "The vernacular is 'to sing.'"

Trump praised Ellis shortly after the hearing, calling him a "very special" and "highly respected" judge and bemoaning that he and Manafort were victims of a "phony Russia witch hunt."

Legal experts said there were at least two reasons Trump's lawyers are interested in Manafort's case.

The first is that Ellis' decision will dramatically affect whether Manafort would flip on Trump.

"If the Virginia case goes away, Manafort won't flip," said Jeffrey Cramer, a longtime former federal prosecutor in Chicago who spent 12 years at the Justice Department. "Conversely, if Ellis finds that it was appropriately brought, then you've got a 69-year-old man facing years in jail at the minimum. He's going to cooperate, period."

Manafort and his deputy, Rick Gates, joined the Trump campaign in March 2016 and stayed on until August. Both were key figures during pivotal events, many of which Mueller is investigating. Gates is cooperating with the special counsel.

Experts also said that if Ellis ruled against Mueller and dismissed the Virginia case, it would create a legal precedent — albeit a nonbinding one — indicating that there are limits to Mueller's powers.

A ruling against Mueller would "support any argument Trump's lawyers may make later that whatever eventual allegations Mueller brings fall outside his scope," said Patrick Cotter, a former federal prosecutor who worked with members of Mueller's team at the Justice Department.

Robert Mueller. Alex Wong/Getty Images

Rosenstein appointed Mueller as special counsel last year. Mueller is tasked with investigating Russia's interference in the 2016 US election, whether the Trump campaign colluded with Moscow to tilt the race in his favor, and whether Trump sought to obstruct justice last year when he fired James Comey, the FBI director who was spearheading the Russia investigation.

In addition to investigating Russia's interference, Rosenstein authorized Mueller to examine "any matters that arose or may arise directly from that investigation," as well as two broad threads as they relate to Manafort:

Whether he colluded with Russian government officials as Russia was trying to meddle in the 2016 election.

Whether he committed any crimes "arising out of payments he received from the Ukrainian government before and during the tenure of President Viktor Yanukovych."

It's 'no secret' Trump wants to sit for a Mueller interview

Trump, meanwhile, is a subject of interest in several threads of the Russia investigation.

He is central to an obstruction-of-justice case Mueller is said to be building against him, based on his decision to fire Comey and his actions in the months that followed.

Mueller is also examining Trump's part in crafting a misleading statement his son Donald Trump Jr. released following reports that he met in Trump Tower in June 2016 with two Russian lobbyists offering dirt on Hillary Clinton, the Democratic nominee.

Mueller's team conveyed a list of 48 questions to Trump's lawyers last month that touch on those events and more, including the firing of Michael Flynn as the national security adviser.

Though Trump's lawyers have advised him against agreeing to an interview with Mueller, the president has been described as "champing at the bit" to sit down with the special counsel.

One source with knowledge of the matter told Business Insider it was "no secret" Trump would like to testify but added that the president would have to waive his executive privilege to do so. The person said that such an interview, under the existing circumstances, would not be a good idea because "there's no evidence produced of wrongdoing."

"You don't want to create a case against yourself by people lying," this person said, noting that the decision would ultimately be Trump's, based on the advice of his legal team.