Political attacks are difficult to get right, because there is often a yawning chasm between the messenger and the target audience. You may believe – with every fibre of your being – that your opponent is cruel, evil, a danger to all people everywhere. But so what?
Tony Blair, until recently Labour's only living election winner, implicitly understood this. That is why he called John Major 'weak', William Hague 'better at jokes than judgement', Michael Howard an 'opportunist' and David Cameron a 'flip-flop'. These were all fairly low wattage, and that was by design. Blair explained in his memoirs:
