When United Flight 93, the fourth plane hijacked in the September 11, 2001 terrorist attacks, crashed into a field near Shanksville, Pennsylvania, the gash it left in the ground became a national site of mourning. The flight’s 40 passengers became a media obsession, and countless books, movies, and articles told the tale of their heroic fight to band together and sacrifice their lives to stop Flight 93 from becoming a weapon of terror. In Angel Patriots, Alexander Riley argues that by...