The most famous TV election debate image is a sweaty and unshaven Richard Nixon up against the telegenic JFK in the US in 1960. Here in the UK, the most decisive debate game-changer was Gordon Brown and David Cameron conceding "I agree with Nick" in 2010. That sparked the "Cleggmania" which propelled Nick Clegg to the post of deputy prime minister in Mr Cameron's coalition government. Mr Nixon's disaster under the harsh TV lights came in the first TV debate held in a US presidential election, one of four during the 1960 campaign. At the time, Mr Nixon was Republican...