What Does The Phrase 'Drinking The Kool-Aid' Mean?

It means to mindlessly follow the instructions of a higher authority. Kool-Aid is an American soft drink which comes in powdered form and has water added to it. The phrase 'drinking the Kool-Aid' comes from an incident in Guyana in 1978 where hundreds of followers of cult-leader Jim Jones, self-styled Reverend of the Peoples Temple, were said to have committed suicide by drinking Kool-Aid mixed with poison. Over 900 people in total died during the mass suicide. Some were reported to have been reluctant and were shot by Jones' armed guards; a few escaped into the surrounding jungle.

The sequence of events had been precipitated by the visit of Congressman Jim Ryan who had grown concerned about reports of people being held against their will at the Jones compound. Ryan visited the facility and several people there expressed a desire to leave with him. As Ryan and his entourage, including several former cult-members, prepared to board aircraft to make the journey back to the United States, some of the Jones cultists opened fire on the group. Ryan and several others were killed. The mass suicide occurred later that day.