Legislating for lunatics
At the same time, there have always been and will always be a few straight-up lunatics in the world who want to kill a politician. A quick run down of the last few decades of attempts in the West, successful and unsuccessful, doesn’t really reveal any sort of pattern – Pim Fortuyn, Anna Lindh, Olof Palme, Jacques Chirac, Zoran Dindic and Queen Beatrice of the Netherlands. It’s hard to discern any theme in that list of victims – and you’d be daft to try. The only British Prime Minister to have been assassinated, Spencer Perceval, was killed by a lunatic (whose direct descendant is currently MP for North West Norfolk) because of a grievance over unjust imprisonment in Russia.
I am instinctively distrustful of the argument that violent rhetoric causes violence – just as I am distrustful of the argument that violent computer games cause violence. The attempted murder of Gabrielle Giffords was no more the fault of Sarah Palin, than the attempted murder of Ronald Reagan was the fault of Robert de Niro. You cannot, and should not, moderate your speech and desist from using metaphors for fear that a madman in Arizona might take you seriously.