Why Donald Trump pardoned the unpardonable Joe Arpaio

Arpaio, the self-styled ‘toughest sheriff’ in America, systematically abused his powers.Who will go first, President Trump or our constitutional order?The question presses after the president’s most recent affront to our system of governance, his unpardonable pardon of former Maricopa County, Arizona sheriff Joe Arpaio, announced last night in a presidential tweet.