Mr Arpaio, who styled himself “America’s toughest sheriff”, is an authoritarian impresario. He housed county prisoners outdoors in tents, even as temperatures reached 145°F (63°C), made them wear pink underwear and put them in chain gangs, sending them to cut weeds or clean roads in the affluent suburbs where his supporters lived. He recruited a posse of volunteer sheriff’s deputies, who sport police uniforms and roar about in p…