Scott Lucas: Call to fight not a reaction, but a refrain

Can Americans resist the politics of violence and consider how to co-operate with each other

As the protection detail tried to bundle him off the stage in Butler, Pennsylvania, he shouted, 'Wait! Wait! Wait!!!' Then, with his fist pumping upwards, he directs his supporters, 'Fight! Fight! Fight!'.

The photograph by Evan Vucci of the Associated Press is already iconic. 

His ear grazed by a gunman's bullets moments earlier, Donald Trump rises above the secret service agents trying to shield it.