This assumption is just wrong—uncomplicatedly, flatly wrong. It is true that, typically, the 93 (not 96) U.S. attorneys are presidentially nominated and Senate-confirmed. But Congress has established an alternative method of appointment. Title 28 U.S.C. § 546 provides that, until the Senate confirms a presidential nominee, U.S. attorney vacancies can be filled for up to 120 days by an appointment made by the attorney general and then indefinitely by local district courts. Such non-presidential, non-Senate-confirmed appointees are, as one court of appeals has put it, “fully-empowered United States Attorneys, … not subordinates assuming the role of ‘Acting’ United States Attorney.” And such fully-empowered, non-presidentially-appointed U.S. attorneys are not all that uncommon. Today, the sitting United States attorneys in two of the most important judicial districts in the country—the Southern and Eastern Districts of New York—were appointed by the judges of those districts under Section 546(d).

And so “the Congress … by … vest[ing] the Appointment” of U.S. attorneys “in the Courts of law” and “in the Heads of Departments,” obviously recognized that U.S. attorneys are “inferior officers.” But Congress is not the only branch of the government to have reached this conclusion. In 1978, the question was expressly put to the Justice Department’s Office of Legal Counsel. OLC’s conclusion: U.S. attorneys are inferior officers, because the law “authorizes the Attorney General to direct all U.S. Attorneys in the discharge of their duties.”

Not to be left out, members of the third branch—which has made a lot of these appointments—have also agreed. The Supreme Court has never squarely addressed the point under the Appointments Clause, but in discussing presidential removal power in Myers v. United States, the Supreme Court specifically referred to “a United States attorney” as an example of “an inferior officer.” More recently, in Morrison v. Olson, the high court approvingly noted how “Congress itself has vested the power to make [U.S. attorney] interim appointments in the district courts” under 28 U.S.C. § 546(d), and observed that “[l]ower courts have also upheld [those] interim judicial appointments of United States Attorneys” under the Appointments Clause. These lower courts include two federal courts of appeals, one of which rejected an Appointments Clause challenge to a U.S. attorney who had served under a judicial appointment for more than six years.

Accordingly, there is no serious dispute: U.S. attorneys are inferior officers. So if what Robert Mueller is really doing is, as Calabresi suggests, “behav[ing] like the [93] U.S. Attorneys,” then Calabresi’s argument immediately collapses on itself. Mueller is an inferior officer, just as U.S. attorneys are.

But it is even worse than that for Calabresi’s thesis—Mueller’s Office of Special Counsel appears, on its face, to be inferior in size and authority than many, if not most, U.S. attorney’s offices throughout the nation.

As the president is wont to point out these days, Mueller’s office consists of few more than a dozen lawyers—roughly the size of the U.S. Attorney’s Office for the District of Wyoming—and the scope of his work is quite narrow. Contrast some of the larger U.S. attorney’s offices—such as that of the court-appointed U.S. attorney for the Southern District of New York. That office comprises roughly 220 lawyers, and the scope of its work is breathtaking—covering, just for starters, “domestic and international terrorism, white collar crime, securities and commodities fraud, public corruption, cybercrime, narcotics and arms trafficking, gang violence, organized crime, and civil rights violations.” If the U.S. attorney who runs that office is an “inferior officer,” then so too is Robert Mueller.