At a time when our discourse has become so sharply polarized – at a time when we are far too eager to lay the blame for all that ails the world at the feet of those who happen to think differently than we do – it’s important for us to pause for a moment and make sure that we’re talking with each other in a way that heals, not in a way that wounds.

So said President Barack Obama at a memorial service held four days after the attempted assassination of Democrat congresswoman Gabrielle Giffords at a shopping centre in Tucson, Arizona, on 8 January. The shooting of Giffords and eighteen bystanders – six of whom died – has triggered much debate in the United States as to whether there has been an escalation of violent words and images since the election of Obama and the advent of the insurrectionist-minded Tea Party Movement. On the face of it, there appears to be a case to answer.