Even before the most basic details of the shooting at Donald Trump’s Pennsylvania rally yesterday had emerged, the ceaseless, grating background noise of American political life had cranked itself up once again.

You might imagine that a possible assassination of a leading presidential candidate would be a scared-straight moment for a nation that has been sleepwalking into a culture of political contempt, delegitimization and tribalism. But before anything, it was right back to reflexive criticism of the media, vitriol for the other side and conspiracy theories.

The shock: Someone was apparently able to take multiple shots at a former president of the United States, protected by a phalanx of Secret Service and surrounded by a throng of citizens.

The non-shock: Yet another person in the United States was apparently willing to engage in potentially lethal violence in the arena of politics, the latest in a sorry trail that has menaced elected officials, judges, civilians, the Capitol and now a leading presidential candidate.