We all know that peer pressure can be a dangerous thing. Drinking the Kool-Aid is an American phrase for those people or group who knowingly pursue a dangerous idea.
For example…
Did you know that “Drinking the Kool-Aid” was ranked number one in the Forbes magazine’s poll of the “single most annoying example of business jargon” in February 2012? In the US, it is often used when referring to unpopular political figures and even by people who want to distance themselves from them. For instance, Jon Meacham, Newsweek editor at the time, said in a 2009 speech, “I did not drink the Obama Kool-Aid last year”.