“Never underestimate the power of stupid people in large groups.”

Ad Populum or Bandwagon

Appeals to popularity or the fact that many people do something as an attempted form of validation.

The flaw in this argument is that the popularity of an idea has absolutely no bearing on its validity.

A Bandwagon Fallacy:

• is also called Ad Populum or and appeal to common belief

• relies on people willingness to believe what is popular without demanding evidence.

What is a bandwagon?

The name "bandwagon fallacy" comes from the phrase "jump on the bandwagon" or "climb on the bandwagon", a bandwagon being a wagon big enough to hold a band of musicians. In past political campaigns, candidates would ride a bandwagon through town, and people would show support for the candidate by climbing aboard the wagon. The phrase has come to refer to joining a cause because of its popularity.