Most of the stories told about Benjamin Moore, 23, at his funeral started in a bar and ended in a laugh. Invited to testify about his life from the pews, friend, relative, colleague and neighbour alike described a boisterous, gregarious, energetic young man they'd known in the small New Jersey town of Bordentown since he was born. "I'll love him 'til I go," his granny said. "If I could go today and bring him back, I would."

The state of the union speech has a specific and particular role in the American polity's calendar. Masquerading as an event of political import, it is, in fact, a much-trailed setpiece of mediated theatre in which the entire political class pledges itself to eternal optimism: America's endlessly renewable resource. Somewhere in the speech, regardless of how much of a mess the country is in, the president will insist, to roaring applause from both sides of the aisle: "The state of the union is strong." It is one occasion when the president is supposed to embody the resilience of national will over material fact.

Jared Loughner, the suspect in Saturday's shooting spree in Arizona, was not working alone. True, the rampage apparently emerged from his confused, unstable and troubled mind. But it was also the byproduct of a polarised political culture underpinned by increasingly vitriolic, violent and vituperative rhetoric and symbolism.