Groupthink

In an article from Psychology today, they state "Groupthink occurs when a group of well-intentioned people make irrational or non-optimal decisions that are spurred by the urge to conform or the discouragement of dissent"... "Groupthink fosters a strong "us versus them" mentality that prompts members to accept group perspectives in the heat of the moment, even when these perspectives don't necessarily align with their personal views."

We have most likely all been in a situation where group think played a big role and/or took over.