A derogatory term for the portion of society who are too stupid or ignorant to be allowed to make decisions.
The term originates from the multitude of "Stupidest things Americans believe" surveys conducted in 2011 showing an alarming trend that roughly 20% of the American population believe ridiculous things.
(eg. 20% of Americans believe; that witches really exist, that they know someone who has been abducted by aliens, that Obama is a Muslim, that the sun revolves around the Earth, etc.)
Alternate pronunciation: "twenty percenter"
You think that dinosaurs and humans lived at the same time?!? You're one of the 20% aren't you?
Can we switch seats? This 20% won't stop talking about how the world is going to end in 2012.