Husp is a slang term for the Human Supremacists native to New Pale. The group practices a philosophy called human superiority. The members of HUSP preferred the isolation of New Pale and did not want it "contaminated" by the other races. Pale used its military to coerce the weaker government into allowing other races to settle there. Pale saw this as a way to increase food production on New Pale and perhaps drive food costs down. 

Several months latter, the HUSPs banded together and began terrorizing the new colonists, also attacking Pale's "colonial protection" forces.

The government of New Pale has virtually become a puppet but there is a dissident underground government that claims to be the only legitimate government of New Pale. Members of HUSP and other groups form this congress but it serves as little more than a mouth piece for spouting hate and racially-colored speech.

(cited from Dragon Magazine issue #98, The Volturnus Connection, by Stephen Bonario)

Pure Strain Humans: PSH are decendants of Ancients that were genetically engineered, they are different than humans of RL. They look down on other humans and mutant humans considering them inferior or unpure, genetically contaminated.  One group of PSH known as the Knights of Genetic Purity or "Purists" who wish to destroy all mutant humanoids, thankfully they are uninterested in destroying mutant plant and animal life as they do not know it is mutated. They wear a bright red square, printed, painted, or emblazoned in some way on the fronts of their garments or armor.  Some Gamma World sources indicate that the PSH maybe genetically stable or resistant to mutagens becuase of they were genetically modified by design to be superior to normal humans, the future humans were modifiied to weed out genetic diseases, live longer and so on are gentically manipulated beings themselves. Latter this idea developed: They are the descendants of the very rich and powerful, who before The Fall received rejuvenation treatments (GST- genetic stabilization treatment) in the form of nano-machines to keep themselves young, fit and strong. The nano-machines were designed to prevent their DNA from becoming mutated; to them, it was just a cure for cancer and general rejuvenation. The mega-corporations who invented these nano-machines, in order to prevent their spread from the paying host (of course, so that they could continue to charge exorbitant prices for something that would be dirt cheap if they didn't implement artificial scarcity), designed them so that the machines would imprint on the first host's DNA, and not operate on other's DNA. However, the artificial scarcity plan had one drawback: the nano-machines would imprint on a woman's egg cells as well, and therefore could be passed from generation to generation. When The Fall came, those who had received the treatment found that they and their children would not develop mutations like those around them, thanks to the nano-machines. the GST- genetic stabilization treatment is mentioned in Dragon 106 and the concept was folded into 1e Famine in Fargo. Those who didn't get it were either mutated or their offspring mutated or have just been lucky (living in some protected place, or in cold storage some place, or cloned off of unmutated DNA) but if exposed to mutagens will mutate or children will be born mutant.

So xenophobia, superiorists type arche types in the two games.

Obviously this tech is doable for SF too and this sort of privileage or even social stignma towards non genteically engineered humans occurs in several movies: Gattaca would be an example suitable for SF ideas about how Natural Humans vs Geneticaly Engineered might be treated in society, Humanity's End a not so great film but with lots of different kinds of humans all trying to wipe each other out. Normal Humans were created by Neanderthal (which became the Nephilim by genetic modification and possible alien DNA the most advanced ones live super long periods) from their DNA to be slaves, (latter after a bunch of wars and humans destroying the Nephhilim), humans genetically begin improving themselves... so you have Normal Humans (who use gentic screening grading system for breeding purposes), genetically engineered clones of various kinds which are slaves, nuetered often killed when no longer needed or obsolete, one group known as Konstructs (genetically engineered to gradually become superior humans) who are not slaves or nuetered having their own colonies, biobots sort of clone/cyborgs made as human as possible some have human overies and can reproduce with human males resulting in a normal human child, and the Nephilim who want their homeworld back, really want to wipe all humanity out, and want some ancient DNA to regain their immortality. Basically lots of different Space Humanoid/Humans all thinking they are superior, the best and so on.

Space Humans... Future Humans. 

As a side note in my background for SF the Sathar are freaked about Humans and Vrusk/Clikk like races as they descend from ancient races that nearly wiped out all alien sentient life or oppressed it with their Empire Building but no Human or Vrusk type alien remembers that as everyone pretty much who survived the Great Galactic War and the following Dark Ages where reduced to primitives... but the Sathar know enough and see Vrusk and Humans together as the ultimate threat to all life. My bad guys have a reason for doing what they do.