Arpaio faces a June 26 bench trial in Arizona U.S. District Court stemming from alleged contempt of a 2013 federal court order intended to stop his agency from racially discriminating against Hispanics.
U.S. District Court Judge Susan Bolton denied Arpaio the right to a jury trial in the case earlier this month. The U.S. Ninth Circuit Court of Appeals upheld her ruling last week.
His lawyers assert in a 47-page motion to the High Court that failing to grant Arpaio a jury trial would be "undemocratic."
Besides that, he's too old to wait around for an appeal should he be convicted, the document argues.
"Defendant will suffer a wrongful trial and could suffer a wrongful sentence," wrote lawyers from local firms Goldman & Zwillinger, PLLC, and Wilenchik & Bartness, P.C. "If Defendant, who is eighty-four years old, dies before a reversal on direct appeal, then the sentence will stand."
Arpaio's argument centers on the idea that a conviction by the federal court, if it comes down to that, would not be seen by the public as legitimate.
If the Supreme Court doesn't allow a jury trial, "then the district court will be sitting in judgment of its own prosecution of the defendant, an elected officer in a 'competing' branch of government," the petition states.
"This already subjects any verdict to a certain degree of public suspicion, other than raising the specter of something undemocratic. But if the verdict is reversed on direct appeal (for failure to grant a jury trial), then it strongly signals to the public that the district court lacked independence or fealty to our democratic system."
Jack Wilenchik, one of Arpaio's lawyers, told New Times on Thursday that "the right to a jury trial is sacred. It's the foundation to our democracy."
The petition also the court to consider delaying the bench trial if the justices can't reach a decision on the petition before June 26, noting that Bolton has denied any further delays and that the petition is Arpaio's final opportunity for a stay of trial.
Arpaio wants the U.S. Supreme Court to decide quickly whether to take the case. He wants the court to consider the petition at its June 15 conference, "otherwise, the occurrence of trial will render his Petition moot."