Flouting convention and common sense alike, President Donald Trump has dispensed a pardon to one of his favorites, former Maricopa County Sheriff Joe Arpaio, an Arizona vigilante with a badge who for years used the powers of his office to terrorize Hispanics and those in his custody.

In doing this, Trump disregarded the detailed guidelines for pardons established by the Justice Department, which include a five-year period elapsed since conviction, along with demonstrated remorse and an acceptance of responsibility for the crime committed. Trump did not even consult his own attorney general, except for a questionable inquiry earlier as to whether the case against Arpaio could be dropped.

Trump's decision displays once again his contempt for the judiciary whenever it clashes with his own wishes — and his unerring instinct for creating yet more division in a country already badly polarized. Coming on the heels of Charlottesville, it is a particularly disturbing signal to minorities who already feel at sea under this president.

Arpaio himself is an insult to sheriffs who labor daily to protect citizens, uphold the law and grapple with the many societal problems those tasks involve. His desire for notoriety led him first to bully inmates in his custody, creating tent cities he likened to "concentration camps," deputizing civilian posses and creating female inmate chain gangs. He then moved on to targeting immigrants, conducting sweeps through Latino neighborhoods and stopping anyone he thought "looked" illegal.

The federal investigation that Arpaio has called a "witch hunt" by former President Barack Obama actually began under Republican President George W. Bush nearly a decade ago. The pardon has drawn condemnation from many, including former Arizona U.S. Attorney Paul Charlton, appointed by Bush, who said recently that in pardoning Arpaio, "you are acknowledging that racist conduct in law enforcement is worth the kind of mercy that underlies a pardon — and it's not. It's an abuse of the president's discretion. It's an injustice and speaks volumes about the president's disregard for civil rights …"

The man Trump called "a great American patriot" was found by a federal judge to have used racial profiling to violate the constitutional rights of Latinos, many of whom were U.S. citizens or legal immigrants. Arpaio blatantly ignored the federal court order to stop and was bounced by the voters of Maricopa County last November, just as Trump — whom Arpaio ardently supported — was ushered in as president. The bond between Trump and Arpaio stretches back to their ceaseless stoking of birtherism, in which Arpaio went so far as to use public funds for a failed "investigation" of Obama's Hawaiian birth records — a move hailed by Trump at the time.

The cruel record of this rogue lawman is open for anyone to see. Sworn to uphold the law, Arpaio instead flagrantly defied it. He should have been held to the highest standard. Instead, without expressing remorse or admitting responsibility, he is rewarded by a president determined to prove that his is the only decision that matters.

That Trump would employ his virtually unlimited pardon powers to grant clemency to such an individual — who continues to mock and defy the courts — is as unfathomable as it is unnerving.