Classism

Classism is prejudice or discrimination based on economic class. It can refer either to individual attitudes or systemic class-based oppression endemic to a society. It is often associated with philosophies relating to social Darwinism and eugenics.

Almost universally, classism specifically denotes the predjudice against and subjugation of those in the lower classes by the more privileged upper class. (see Reverse racism)

Counter-examples to the aforementioned trend invariably take the form of childish whining.

Classism could be considered a central concept in Marxism, which advances the idea that systems of class-based oppression and exploitation (the foremost example being capitalism) result from pre-existing material relations of production. In this context classism is not seen as a direct cause for social inequity, but rather as a form of class conflict driven by the dominant bourgeois perception of society.

Forms of classism
Classism generally takes one of two forms (which are by no means mutually exclusive). The first is natural hierarchy, namely the belief that a particular caste has the innate right to rule due to biology or divine right. This was extremely common in Europe up to the 19th century due to the concept of the divine right of kings. It is also incredibly common in India, where certain fundamentalist forms of Hinduism (as well as the political ideology Hindutva) view the upper castes (namely the brahmin and kshatariya castes) as innately superior. The second is economic hierarchy, which is by far the most common in the Western world. It is the belief that rich people within a capitalist system are somehow more intelligent or more virtuous and that lower-class people, typically either working-class people or lumpenproletariats (namely criminals and benefit claimants) are good for nothing scum. This socially Darwinian view is extremely common within right-libertarianism and conservatism in the United States and the UK, exemplified perfectly by Ayn Rand's concept of the parasite and the producer.

"The Poors"
"The Poors" is a curious term you'll see almost exclusively on liberal/progressive blogs and may need a bit of explaining.

The term refers to poor people (obviously), but in this context it's meant as a slam against a third party, namely well-off people with classism issues who tend to blame poor people for their state in life. The specific construction of the word is by analogy with vaguely dehumanizing uses, like "the Catholics", "the blacks," or "The Jew."

You'll actually rarely find the wingnuts who the term targets using it because it's intended as a caricature. It should go without saying that if you use "the Poors" unironically, you're probably an asshole.

Examples

 * First world problems: Poor people in the first world shouldn't complain because poor people in the third world have it worse.
 * Meritocracy: Poor people are poor because they're lazy.
 * Welfare queens: Poor people mooch off the government's taxpayer dollars.