"Hello. My name is Draco Malfoy. My parents are Lucius and Narcissa Malfoy. Just based on that, guess if I'm a nice guy or an evil little snit. Just guess."
Draco is very proud of being a pure-blooded wizard, meaning all of his ancestors were wizards. You know what that means: like the British monarchy, he's the result of lots of inbreeding. I think that explains a lot of the attitude problem (and the easy bleeding).
Draco if a snob and a bully around Hogwarts, but it's a funny kind of bully given that things almost never go his way at all. Whenever he opens his little mouth, he usually winds up being turned into a ferret or getting a bloody nose from a girl. After a while, it's kind of hard to even see Harry as the underdog in their rivalry. Harry's famous and (usually popular), both of them are rich, and Harry always wins. I guess that's why, at the end of the series, Draco renounces his family fortune and builds a cabin in the woods where he can live by the sweat of his brow and be a friend to all the woodland creatures (this does not really happen).