Re: Supernatural4x21 "When the Levee Breaks" episode discussion/spoile
Hunters are sort of like the Klu Klux Klan, only less well organized and instead of lynching Negroes they lynch non-humans. It just so happens that most of the non-humans that we see are ruthless murderers, but most hunters don't care about the guilt or innocence of their victims. Sam has compassion and empathy for non-humans, to a sufficient degree that he can love and trust one. Dean does not. He was raised to hate all "monsters" and for the most part he does. Sam has been able to pull him back from committing some vile atrocities against the innocent at times, but just barely.
Consider the events revealed in Jump the Shark. John Winchester murdered a man whose only crime was stealing food for his family. That food just happened to be dead bodies. It may have been disgusting, but it wasn't harming anyone. John was a moral person with a strong sense of right and wrong, he'd never kill an innocent man just trying to feed his family. If that man hadn't been a ghoul, if he hadn't been racially impure, then John would never have hurt him. In the mind of most hunters, being racially impure is a crime, one punishable by death. It is a mindset that Dean shares. To him, the sub-humans have to prove that they are worthy of life.
Right now, Dean is in the same position that Cyrus Dorian from Route 666 was in before his death. Sam, whom he loves in a very disturbing but explicitly non-sexual way, has betrayed him in favor of a demon, a monster, a sub-human, a mud-person. So he does what any reasonable hunter would do, what Cyrus Dorian did for his lover, he attempts to save Sam by murdering the ethnically inferior hypotenuse of their twisted little interracial pseudo-incestuous love triangle.
But Sam, he rejects this act of love. And worse, he consumed her blood. That's almost as bad as a Nazi getting a transfusion from a Jew. It practically makes him an Untermensch himself. But it's worse, because those poor people have no choice, but he's willingly giving up his innate racial superiority.
Dean doesn't want to see that happen. He doesn't want to see his brother loose his birthright as a member of the Master Race and will do anything to stop Sam from throwing that away.
Sam's basically a white supremacist who just found out that one of his great grandparents was black and chose to deal it constructively and explore the truth, while Dean feels that he's loosing his brother to the mud-people and that's making him an even more hardcore racist than he already was.
It doesn't help that there really is a Zionist-Communist conspiracy to undermine the Fatherland and that it's Elders really do have Protocols.