#muggle-born

Ron first explains what the term means: “Mudblood’s a really foul name for someone who was Muggle-born - you know, non-magic parents.” Next, he gives more context: why is this term used as an insult, what kind of people use it: “There are some wizards - like Malfoy’s family - who think they’re better than everyone else because they’re what people call pure-blood.” He then goes on to explain “the rest of us know it doesn’t make any difference at all”.

So far so good, Ron’s exposition was over with these lines. But the really striking thing is this: 

“It’s a disgusting thing to call someone [...] Dirty blood, see. Common blood. It’s mad. Most wizards these days are half-blood anyway. If we hadn’t married Muggles we’d have died out.”

This further demonstrates Ron’s anger and indignation on Hermione’s behalf, but it also shows something quite interesting: Ron understands that the concept of blood purity is inherently flawed and ultimately meaningless. Sure, he puts it in terms of blood purity (“Most wizards are half-blood anyway”), but this is only because the concept is so deeply ingrained in wizarding society. This actually makes it more impressive that Ron seems to have so deeply assimilated exactly why the pure-blood supremacist ideology is so wrong.

He could have stopped at saying that it’s “disgusting”, “foul”, and simply been offended on behalf of one of his best friends. But the explanation that Ron gives of why the ideology is so ridiculous shows that he really understands the argument that he is making against it, and that, despite being young, he is politically committed to fighting pure-blood supremacy both practically (as demonstrated by his attempt to fight Malfoy) and ideologically.

Ron may not seem the most politically conscious character - that role is often (rightly) attributed to Hermione - but his political engagement is unfairly underestimated (insert rant about the films’ character assassination...). He may not always have the same priorities as Hermione (especially with regards to SPEW, for example), but he is still politically aware. I think the line that prompts Hermione to kiss him in Deathly Hallows (“[...] we should tell them to get out. We don’t want anymore Dobbies, do we? We can’t order them to die for us –”) really shows how susceptible he is to recognising and fighting against injustice the moment he realises how pervasive it really is.

I would argue that pure-blood supremacy as an ideology is something Ron is particularly concerned with because, as we know, his family, and father especially, are considered “blood traitors” by exponents of the ideology. Ron grew up in a family that was dead set against the idea of pure-blood supremacy, and was stigmatised for it. Arthur Weasley’s appreciation of Muggles (whilst arguably problematic) comes much closer to genuine respect than anything other members of the Ministry demonstrate, especially considering that the Minister for Magic is willing to do business with someone like Lucius Malfoy. 

From this I would conclude that the Weasleys are considered relatively extreme in the Wizarding world. Thus they are shunned from society partly because of their poverty but also because of their political position. Let us not forget also that many Death Eaters we know are respected members of society, and come from very rich families. The divide between Muggle-borns and pure-bloods is not one of class, but there is certainly an almost classist elitism which pure-bloods espouse. In Flourish and Blotts, the Malfoys mock the Weasleys’ poverty, as well as Arthur’s work (and place as a “disgrace to the name of wizard”). There may be a hint of this association of pure-bloodedness with class as well as lineage in Ron’s use of terms in the above quoted lines: “Dirty blood, see. Common blood.” Therefore, Ron Weasley’s family background makes him especially prone to be active against this ideology, and puts him in a position to fully understand it and its implications.

In conclusion, Ron Weasley is far more politically engaged than he gets credit for. Partly thanks to his family background, he is especially committed to fighting pure-blood supremacy. Further, though it takes some time, he becomes active in support of the rights of house-elves in his own right - partly thanks to Hermione, but also thanks to his own willingness to develop strong political feeling.