When David Cameron returned to Tory headquarters early on the morning of 8 May, he declared his sensational election victory to be 'the sweetest' moment of his political career. The Conservatives had won their first Commons majority for twenty-three years and the Prime Minister had achieved the seemingly impossible: increasing his popularity while in government, winning more seats than in 2010 and confounding almost every pundit and opinion poll in the process. Within hours, his defeated rivals