doomsday cult

Coined by American sociologist John Lofland in 1966 in his book Doomsday Cult: A Study of Conversion, Proselytization, and Maintenance of Faith

doomsday cult (plural doomsday cults)

1. A cult that believes in apocalypticism and millenarianism.
2. (by extension) a group that has lost touch with reality.
   • 2022 October 3, Paul Krugman, “How Liz Truss Did So Much Damage in So Few Days”, in The New York Times‎, →ISSN:

     This raised doubts about their competence and, indeed, their connection to reality; it’s never good when economists at major banks declare that a country’s ruling party has become a doomsday cult.

• doomsday cult on Wikipedia.Wikipedia