“Drinking the Kool-Aid”
“Drinking the Kool-Aid” is a metaphor commonly used in the United States and Canada that refers to a person or group’s unquestioning belief, argument, or philosophy without critical examination. The phrase typically carries a negative connotation when applied to an individual or group.
The basis of the term is a reference to the November 1978 Rev. Jim Jones Jonestown Massacre, where members of the Peoples Temple were said to have committed suicide by drinking Flavor Aid (not actually Kool-Aid) drink laced with cyanide.