The Delusions of Faith
"A delusion is a false, unshakeable idea or belief, which is out of keeping with the patient’s educational, cultural and social background; it is held with extraordinary conviction and subjective certainty. ~ Professor Andrew Sims - Is Faith Delusion?"
In other words, perfectly normal people now doing and thinking irrational things. The Trump phenomenon is inexplicable when otherwise sane people suddenly go rabid and take up arms to follow a madman.