Has the mayor of Chicago reinvented the city’s notorious political machine – and does he covet the White House? When Rahm Emanuel became mayor of Chicago in 2011, he proclaimed: “I will not be a patient mayor.” It was an understatement. The former chief of staff to Barack Obama returned home with a near-legendary reputation for his take-no-prisoners style of operating. That is how he acquired the nickname “Rahmbo”. He once famously mailed a dead fish to a pollster with whom he had fallen out. There are few significant Washington figures who have not felt the lash of his tongue....