About Harry Potter and the Deathly Hallows?

To begin I need to say that I am not an obsessed Harry Potter fan, I never finished reading the sorcerer's stone because the movie came out and I own book 5 and 6 but I've never read them. So now that I took that out of my system...

So I was watching Harry Potter and the Deathly Hallows the other day and suddenly all these questions popped in my head. For example, in the 6th movie, the half-blood prince, it's all about how Severus Snape is the half-blood prince! Which means he isn't pure blood because his father was a muggle. So while I was watching Deathly Hallows part 1, I kept asking myself why he belongs to that sort of club Voldemort, Draco, Bellatrix, and so on belong to? I've tried googling the answer but I don't want to read any spoilers, I know nothing of book 7.About Harry Potter and the Deathly Hallows?
Read the books, you don't know what you're missing.
Its not a club, its a group ruled by Voldermort. Draco and Bellatrix are purebloods, same with Lucius and Narcissa. Voldermort himself is a half-blodd, is dad is a muggle. He doesn't care that there are half-blood death eaters(name of the followers) because he wants muggleborns or as they call them mudbloods gone because they say they arnt true wizards and witches because they are not from a wizarding family.About Harry Potter and the Deathly Hallows?
There aren't enough "Pure-bloods" (like Malfoy, Bellatrix, etc.) left in the wozarding world...so Voldemort's Death-Eaters are either actual pure bloods, or Half-bloods pretending.



Don't forget...Voldemort himself is a Half-Blood (this is explained in book 2 (and movie 2-so you should know that)).
like the first answer, they are more concerned with mudbloods. Although they do say that they don't condone the inter-relations of muggles and wizards. BUT... there are really no Pure Bloods left really. Voldemort himself is a half-blood, he had a muggle dad... whom he murdered.About Harry Potter and the Deathly Hallows?
There are 2 possible explanations.



The 1st is (and i think that this one is it) that Voldemort only cares about Mudbloods, and Snape told him information earlier



The 2nd one is that Snape pretended that he is a pureblood.
that's because half bloods are okay.

it's mudbloods (one with muggle parents) who are disliked by wizards associated with the Dark Arts.
As Hermione says, "They only care about Mudbloods. They'd be happy to let half bloods like you are Ron in."

What matters to them is mudbloods, not halfbloods
wow, if you don't read the books, you won't get it!
"Voldemort's club"? You're such a Muggle.
The thing is, there aren't many pure blood's left. That's kind of a problem for the families that want nothing to do with muggles or muggle-borns and wish to keep their families 'pure'. Due to this, they've resorted to inbreeding. So almost all magical families are related in some way.



Anyways, there actually isn't enough pure bloods to account for all Death Eaters, so you do end up with people like Snape in the Death Eater ranks. Heck, Voldemort himself is half-blood.



"The pure-blood families are all interrelated. If you鈥檙e only going to let your sons and daughters marry pure-bloods your choice is very limited; there are hardly any of us left." - Sirius Black



"The Death Eaters can't all be pure-blood, there aren't enough pure-blood wizards left. I expect most of them are half-bloods, pretending to be pure." - Hermione Granger
Firstly, Voldemort himself is a half-blood.

Think of it as WWII. Hitler believed in the Aryan race: blond hair, blue eyes, fair skin, tall, not a trace of Jewish blood, no disabilities.... But Hitler himself was not Aryan. He was short, had brown hair and brown eyes, and it's rumored that he had a bit of Jewish blood in him, too. Also, his followers, the Nazis, were not all Aryan either. Hitler didn't mind, though. His first priority was to exterminate the Jews, and if these Nazis were going to help him, he didn't mind that they weren't completely Aryan.



For Voldemort, he believes in purebloods: He thinks that muggles are unworthy creatures and that muggleborns shouldn't be considered wizards at all. He thinks that it's sick for a wizard to marry a muggle (even though he himself is a product of a witch and a muggle... and he hates both of his parents for that). Voldemort didn't mind that not all the Death Eaters were purebloods.As long as they could help him get rid of the mudbloods, and as long as they were loyal servants, he'd keep them.



And t