Here’s a question. What was the second item on the BBC News the day Boris Johnson won the election? It was the news that Nancy Pelosi, speaker of the US House of Representatives, had chosen to proceed with impeachment articles. The two stories – Johnson’s majority and Trump’s predicament – looked interrelated: as if the UK event had something to teach the US as it enters this year of senate trial and general election. These parallels can sometimes seem a little facile. It might be a lazy habit to think of US presidents and UK prime ministers as pairs: Churchill and FDR, Thatcher and Reagan, Blair and Clinton, Obama and Cameron – and now, Trump and Johnson. But it doesn’t stop us doing precisely that. Pete King, the US Representative for New York’s 2nd congressional district, said: “Boris Johnson’s overwhelming victory is a very positive indicator for President Trump”, pointing to the fact that both men are “unorthodox.” Meanwhile, on the Democrat side, Mark Penn, who chaired Hillary Cl...