On the eve of a presidential election fraught with tension, warning flares are bursting across American skies. From federal and local law enforcement to analysts who track radical groups, concern is high about the possibility that violence could erupt, especially if the vote count drags on for days without a clear winner.
The signals are disturbing: A sharp increase in gun sales. A spike in chatter about civil war in online forums where right-wing extremists gather. An embrace of violent language by President Trump and other leaders. And surveys showing an increased willingness by some Americans to see violence as an acceptable tool against political opponents.