By John Oxley Low turnout in elections is bad for democracy. If we want more people to vote, why not make polling day more of a party? Asks John Oxley It’s polling day in London, and chances are that you’re not going to vote. Well, admittedly, as a reader of opinion columns you are probably among the more democratically engaged – but across the capital, less than half of those eligible will cast a ballot for mayor. Since the post was established in 2000, turnout in the poll has never been more than 45 per cent. For the country’s biggest directly elected position, that’s pretty disappointing. I…