Eventually, after four years of unchecked recklessness which not even popular US president Dwight Esienhower could interdict, US senator Joseph McCarthy was undone by one killer question.

He provided posterity with the synonym for scapegoating individuals for disloyalty usually involving communism, and in his case for making often unsubstantiated  accusations involving the so-called “Red Scare”. He destroyed many careers and ruined lives.

In June 1954 it was legal counsel for the US Army Joseph Welch who turned the tables on the inquisitor by asking him: “Have you no sense of decency, sir? At long last, have you left no sense of decency?” Almost overnight, in the court of public opinion, support for McCarthy evaporated and, in short order, he was censured by the Senate and disappeared soon afterward from public life and attention...