The British General Election of 2017 confounded expectations, in an era when we have become used to having our expectations confounded. When Theresa May announced in April that she planned to hold an early election, she had been in office for a little over eight months. But she was riding high. She had just received the backing of both Houses of Parliament to invoke Article 50 and start the negotiations over Britain’s withdrawal from the European Union. The Conservatives enjoyed leads in the opinion polls of more than 20 per cent. May herself had very high popularity ratings, and was…