Democratic presidential candidates want you to be very afraid. They specifically want you to be afraid of mass shooters and medical bankruptcy. But on both, their scare tactics rely on very bad math.

Beto O’Rourke, the former congressman from El Paso, Texas, has tried to once again jump-start his stalled presidential campaign and is using mass shootings and his own foul language — when did presidential candidates start throwing F-bombs? — to get the motor running again.