In a special free episode of LevinTV, host Mark Levin embraced an argument made by law professor Steven Calabresi, a friend and former colleague of Levin's from the Reagan Department of Justice, that the appointment of special counsel Robert Mueller was unconstitutional.

Levin believes Calabresi made "an overwhelming case" that the appointment of special counsel Robert Mueller violated the Appointments Clause of the U.S. Constitution.

The bottom line: Given the power that Mueller is exercising and the fact that Deputy Attorney General Rod Rosenstein is not supervising his work directly, it is inaccurate to classify him as an "inferior officer" in the Department of Justice. He qualifies as a "principal officer," a class of federal official like a United States attorney that the Supreme Court has ruled must be appointed by the president and confirmed with consent of the U.S. Senate.

Because Mueller was not appointed by Trump and was not confirmed by the Senate, Levin argues, his appointment is not constitutional. Therefore, every action he has taken under the scope of his investigation with powers granted to him by the DOJ is illegitimate, since his very powers are illegitimate.

"Is there any question in your mind that Robert Mueller is not the most powerful prosecutor in the United States today?" Levin asked. "Is there any question in your mind that he's not more powerful than any of the Untied States attorneys?"

Levin believes Calabresi's argument ought to be used by the Trump administration and by the targets of Mueller's investigation to challenge the special counsel's authority on constitutional grounds.

Explore the argument with Levin in depth in this free episode of LevinTV, available at CRTV.

Editor's note: This article has been updated with a link to Mr. Calabresi's legal opinion.