A federal court of appeal on Thursday examined the validity of the appointment of special advocate Robert S. Mueller III to investigate Russia's interference in the 2016 presidential election. The appeal, formed by a partner of Roger Stone, a longtime advisor to President Trump, challenges the constitutionality of Mueller's role in a case that could eventually lead to the Supreme Court. The hearing, which takes place one day after Trump's replacement of the Attorney General, opened around 13:00. with a US Court of Appeals Judge for the DC Circuit, ordering the attorneys to present their arguments as if they were debated on Wednesday morning, while indicating that the Appeals Committee may request additional submissions in light of changes in the Department of Justice. Andrew Miller, a former Stone assistant, appealed after losing his bid to block a subpoena to Mueller's grand jury. Miller has been found guilty of contempt of court, but this decision is pending the outcome of his appeals process. The special advocate team sought to interview a number of Stone associates or bring them before the grand jury as part of the investigation that took place 18 months ago. [Roger Stone associate held in contempt for refusing to testify in Russia investigation] Two district court judges in Washington – one appointed by a Democrat, the other by Trump – have upheld the constitutionality of Mueller's appointment in recent decisions. Thursday's hearing, however, is the first time that an appeal board composed of judges Karen LeCraft Henderson, Judith W. Rogers and Sri Srinivasan will consider the authority of the special advocate. "In all the possible tests, Mueller clearly succeeds in asserting its constitutionality," said Elizabeth B. Wydra, president of the Liberal Center Constitutional Accountability Center, who submitted a memoir of jurists. Miller's legal challenge is supported by the National Legal and Policy Center, a conservative non-profit organization, and is based in part on the arguments put forward by law professor Steven G. Calabresi, co-founder of the Federalist Society. [A timeline of the Roger Stone-WikiLeaks question] During the lawsuits, Miller's legal team said that Mueller was illegally appointed in violation of the Constitution's nomination clause because of his broad prosecutorial powers and his "lack of supervision and control over this conduct." ". Deputy Attorney General Rod J. Rosenstein appointed Mueller in May 2017 following the dismissal of FBI Director James B. Comey by Trump. Rosenstein's involvement came from the fact that Attorney General Jeff Sessions had recused himself in court. The President of the Republic said that he had the power to immediately stop the investigation of the special advocate, but said that he wanted to "let it go". "I could send everyone away now," Trump told a press conference held after the elections on Wednesday, shortly before the sessions resigned at the president's request and were replaced by the interim. Matthew G. Whitaker. Whitaker, who served as the chief of staff of the sessions, would assume The horror of the investigation on the special advocate, said Wednesday an official of the Ministry of Justice. Whitaker does not intend to recuse himself, according to his relatives, about the investigation conducted by the special advocate on the interference of Russia. [Trump’s acting attorney general, Matt Whitaker, has no intention of recusing himself from Russia prove, associates say.] The Attorney General has the power "to move his plays from the game of criminal law enforcement failures in all areas, but that does not give him the power to create a new queen," according to the challenge launched by the Miller team, led by lawyer Paul Kamenar. [Two more associates of Roger Stone testify before Mueller grand jury] The Russian firm Concord Management and Consulting will present a similar argument Thursday before the Court of Appeal to dismiss a indictment of the company established by the special advocate. Concord was indicted with 13 Russian nationals and two other companies accused of orchestrating an influential social media campaign to influence the 2016 election. The three-judge panel is expected to respond to the specific question of whether Mueller is a "senior officer", to be appointed by the president and confirmed by the Senate, or a "lower" member, who may be appointed by the department head. The clause usually requires that officials be appointed by the president and confirmed by the Senate, but allow another group of officials deemed "inferior" to be appointed solely by department heads, the president or a court of law. They are under the supervision of a senior officer. If Mueller is a "senior" officer, his appointment is invalid because he was hired by Rosenstein. [Another federal judge upholds constitutionality of Mueller appointment] Mueller's team, which will be led Thursday by prosecutor Michael S. Dreeben, said the appointment was constitutional because the Attorney General had the power to appoint special councils to "detect and prosecute crimes" and set their homework . According to Mueller's team, an officer is "inferior" if he is subject to the surveillance of officials appointed by the president and confirmed by the Senate. Under the Special Councils Regulation, Rosenstein has supervised Mueller's work and may remove him from office for misconduct and "good cause", including for breach of DOJ policy. "The Attorney General receives a steady stream of information about the actions of the special advocate; he can ask for an explanation for one of them; and he has the power to intervene when he deems it appropriate to prevent a departure from established departmental practices, "according to Mueller's team. In a July decision in the Miller case, US District Chief Justice Beryl A. Howell wrote that "the scope of the powers of the special board fits well within the limits allowed by the Constitution ", in part because it is overseen by a manager, in this case Rosenstein," who is himself accountable to the elected president. " Miller worked for Stone, a longtime friend, Stone, during the 2016 presidential campaign, in tasks such as setting up media interviews. He is one of at least nine partners of Stone contacted by prosecutors so far. Stone repeatedly reiterated that he was not in contact with WikiLeaks, who had released Democratic e-mails allegedly hacked by Russian prosecutors and allegedly published in the last few months of the race for the presidency. After Howell's decision, an August opinion by US District Judge Dabney L. Friedrich, appointed by Trump, also confirmed Mueller's appointment. Friedrich rejected a separate challenge from the Russian company Concord, accused of funding an Internet trolling operation targeting US voters. Concord pleaded not guilty to the charge of plotting the election. Rosalind S. Helderman contributed to this report. .