Harry Potter and the Sorcerer's Stone
How we cite our quotes:
"I think I can tell who the wrong sort are for myself, thanks," he said coolly.
Draco Malfoy didn't go red, but a pink tinge appeared in his pale cheeks.
"I'd be careful if I were you, Potter," he said slowly. "Unless you're a bit politer you'll go the same way as your parents. They didn't know what was good for them, either. You hang around with riffraff like the Weasleys and that Hagrid, and it'll rub off on you." (6.246-248)
Being the right sort or the "wrong sort," worrying about being Sorted… Everybody in this book is worried about what "sort" of people they are and with whom they belong. Often, characters make themselves feel better by labeling the opposing side as the "wrong sort" or "riffraff."
You might belong in Hufflepuff,
Where they are just and loyal,
Those patient Hufflepuffs are true
And unafraid of toil… (7.33)
When the Sorting Hat describes the different houses, it emphasizes Hufflepuff's loyalty. Students in other houses may be braver, or cleverer, but the Hufflepuffs are "loyal" and "true." Some of the other Hogwarts kids could learn a lot from them.
Don't you care about Gryffindor, do you only care about yourselves, I don't want Slytherin to win the house cup, and you'll lose all the points I got from Professor McGonagall for knowing about Switching Spells. (9.132)
Hermione proves her loyalty to Gryffindor while simultaneously questioning Ron and Harry's – a comparison made neater by the fact that they share their house. Hermione doesn't help her case by mentioning the points she's gotten for studying, but she's wrong when she accuses the two boys of "only car[ing] about [them]selves."