Arpaio, 85, was found guilty of contempt for violating a federal judge’s order to stop detaining citizens on suspicion of being illegal immigrants. Bolton ruled the pardon was constitutional and rejected the novel argument by Chemerinsky that a contempt conviction is not an “offense against the United States” within the meaning of the Constitution’s grant of pardon power in Article II.
None of this means that the pardon was wise or just but it was constitutional.