Today, at the Tories' spring conference in Brighton, David Cameron will deliver what will be widely and hysterically trailed as the "speech of his life". Well, he's delivered a fair few of those in the past four years, and he certainly has a talent for the genre. The Tory leader has grown used to the hyperbole that precedes such performances. Which is not to say that he is blasé about today's address. Far from it: this will be a speech without notes, and – given the Tories' position in the opinion polls – it has to be a belter.