His rap sheet is a mile long, littered with threats of violence. His van is a mobile shrine to toxic political hatred.
It boiled over when, according to the FBI, Sayoc cobbled together 13 crude pipe bombs and sent them by mail to mainly leading figures in the Democratic Party, a shocking act of what can only be described as domestic terrorism.
As troubling as all of that is, there is another certainty: He is not alone, and we have no idea how many more like him are out there, people teetering on the brink of violence, waiting for that little nudge to coax them over the edge.