CNN

Twice within two months, America has narrowly avoided the tragedy of seeing a major political figure assassinated during an election season — and the toxic forces that such an outrage could unleash in a country wracked by visceral partisan divides.

That such incidents happen at all speak to the undercurrent of violence that is a constant shadow over American politics, one that is exacerbated by the easy availability of firearms. Both nominees now address outdoor crowds from behind bulletproof screens. There will now be fresh fears that a tempestuous period running up to Election Day could take the country further down a dark road.

After decades without an assassination attempt against a high-level executive branch official, a haunting reality has been revived this year: that those who offer themselves for the highest office are potentially putting their lives on the line.