Every single U.S. president since 1860 who was elected during a year ending with a zero had either been assassinated or had died in office before his term was up. Every single one, dead. One way or another. No one will ever know. The idea of intervention has been around for centuries.
Some people use prayers.
They swear by them. Others pray for bad things to happen. These are known as Curses. Curses have their consequences sometimes delivering the scheme back to its maker in a harsh fashion. While Wolff and Byrd deal with curses and demons on a humorous, professional level the story of the Devil in the law is well known.