The "Appointments Clause" provides that "principal officers" must be appointed by the President with the Senate's consent." But the Mueller team was given "special status" to several prosecutors on his team, by Deputy Attorney General Rod Rosenstein in their probe of former Trump campaign chief Paul Manafort, the entire investigation may be invalidated, thus "unconstitutional!"
The self-inflicted "catch-22" scenario by Rosenstein giving unlimited power to Mueller is exactly what the "Appointments Clause" under Article II of the Constitution was designed to prevent.
The Mueller attorneys presiding over the Manafort case before Federal Judge T.S. Ellis III, in Alexandria, VA., may have violated Article II of the Constitution because they not only represented the office of the special counsel, but also simultaneously considered "Special Assistant U.S. Attorneys." Therefore Mueller, (who's the direct supervisor) should be legally considered a "roving" U.S. Attorney.
Now here's where it gets dicey, under the Constitution only the President can nominate all "principal officers," including U.S. attorneys and cabinet members. However Deputy Attorney General Rod Rosenstein appointed Mueller as special counsel. Moreover, Rosenstein is a "political appointee" and as such was never "confirmed" by the Senate, as anyone serving as a U.S. attorney by law must, thus the entire investigation may be invalid. The case can be made that Rosenstein usurped the authority of the President of the United States to nominate whoever he wants as a prosecutor. Mr. Mueller is serving unconstitutionally in violation of the Appointments Clause of the U.S. Constitution because of the way Rod Rosenstein appointed him. All attorneys involved could openly challenge whatever subpoenas the Mueller team throws out, to raise as a defense, the Appointments Clause in court.
This Mueller probe has been illegal since the start and is set to ultimately fail. This isn't a dodge by the Right, just another example of how desperate the Left is to try to hang this President any way they can to nullify his election.