Former Arizona Sheriff Joe Arpaio is back at the Supreme Court fighting critics who want to invalidate his pardon by President Donald Trump.

Congressional Democrats, constitutional law scholars, and former Obama administration lawyers argue that presidential pardon powers don’t extend to Arpaio, who was convicted of violating a court order over his immigration enforcement practices, not a federal law.

But they may first have to get an answer on a crucial technical point that the self-described “America’s Toughest Sheriff” raised in his petition to the Supreme Court: Can federal courts appoint a special prosecutor to argue against the pardon when both he and the Justice Department agree that it should remain in effect?

If the validity of the pardon is left unresolved, Arpaio’s case could set a precedent for future presidents, and perhaps governors, too, over “interfering in all kinds of state or federal court litigation,” George Washington law professor Joan Meier told Bloomberg Law.

That could undermine courts’ ability to enforce their rulings through contempt proceedings.

Special Prosecutor Appointed

Trump pardoned the ex-Maricopa County lawman in August 2017 after a federal judge found that he’d flagrantly disregarded an earlier order to stop racially profiling Latinos suspected of entering the country illegally.

U.S. District Judge Susan Ritchie Bolton subsequently said the pardon didn’t erase the underlying facts or his conviction, and refused to throw out her contempt finding.

The U.S. Court of Appeals for the Ninth Circuit appointed a special prosecutor, Boies Schiller Flexner attorney Christopher G. Caldwell, to defend Bolton’s decision after the Justice Department said it wouldn’t.

Arpaio says courts can’t substitute in another attorney just because they don’t like the Justice Department’s position. Doing so undercuts the idea that courts are impartial deciders, Arpaio’s attorney Jack Wilenchik said.

In appointing a special prosecutor, the Ninth Circuit pointed to the Supreme Court’s “long-standing practice” of naming “disinterested counsel to represent the position taken by the United States” in lower courts when the government “refuses to defend its prior position” at the high court.

The Supreme Court, though, usually appoints an amicus to defend a decision once it reaches the bench. Here, the Ninth Circuit, which still “holds” the case, appointed a “special prosecutor.”

The difference isn’t semantics.

An amicus is someone who is not a party to the case, University of Baltimore law professor John Bessler said.

A special prosecutor, on the other hand, replaces the Justice Department as the party prosecuting the case, Wilenchik said.

The positions taken by the special prosecutor could prohibit the government from changing that position in future appeals on the scope of the president’s pardon power, Wilenchik said.

That’s a problem given that the DOJ doesn’t agree with the argument the special prosecutor has been asked to make, Wilenchik said.

The Justice Department and Caldwell didn’t return requests for comment.

Second Bite

Another issue, beyond binding the DOJ to positions with which it doesn’t agree, is that the special prosecutor could get “a second bite at the constitutionality of the pardon apple,” Meier said.

Bolton, the district judge, already determined that Trump’s pardon was valid. That decision wasn’t appealed by the Justice Department, or anyone else.

All that’s left for the appeals court to decide is whether Arpaio’s conviction should be wiped from the record, or whether the pardon merely protects Arpaio from further punishment.

The special prosecutor was appointed to argue that the conviction should stand.

But in dissenting against the appointment of a special prosecutor, Ninth Circuit Judge Richard C. Tallman said the true purpose behind the appointment was to once again challenge the underlying pardon.

Meier said “it would not be the first time an appellate court had allowed rules to be stretched in the interests of justice.”

“Given the significance of the issues surrounding the pardon” endeavoring “to ensure that this matter is properly litigated, on both sides, seems reasonable,” Meier said.

The high court will consider whether to take up the petition about the special prosecutor this spring. The odds that the justices take up any given petition are low but if they decide to hear the case, arguments likely would be next fall.