"In all four presidencies – Clinton to Trump – the president began his term with a House of Representatives under control of his party (a key to successful governance in America). Three of the four lost the House in their first mid-term election. Mr Bush lost it at his second mid-term. And yet, Mr Trump’s three predecessors were all re-elected, in Mr Bush’s case to the astonishment of pollsters, pundits and the opposition. In 2020 will the chain be unbroken?"