"You're just like your father, Draco."
He was used to hearing those words. Whether it was people showing false approval and pride, or people calling him out on his cowardice, he'd heard it all before. He hated it. The last person he wanted to end up like was Lucius.
Lucius was weak and spineless, and would never face the music for the things he had done. He had power over people that he'd earned by cheating, lying and threatening, and he used it to avoid ever suffering the consequences of his actions. He liked to make others suffer for them. For years, Draco had tried to convince himself that his father felt guilty for doing so; that was why he lashed out so much. That was why he spoke so coldly to him; he didn't want him to turn out the way he did. But as the years passed, all Draco felt toward his father was resentment. Things never got better. If anything, as he got older, things only got worse. Draco, in Lucius's eyes, was the family disappointment, and he made it more than clear with his snide remarks every holiday.
"Why in the world were you incapable of getting a higher grade than a filthy mudblood?" "How could you, a Malfoy, lose a game of quidditch to Gryffindor? You're an insult to Slytherin!" "Draco Malfoy, you little imbecile, all you do is cause me trouble. You may as well be a Potter."
Draco envied Potter. People loved Potter. People were proud of Potter. People didn't sneer when they said the name "Harry Potter"; aside from himself, of course. But, most importantly, Potter's father had been brave; brave enough to die to save him. Draco didn't doubt for a second that, if it came down to it, Lucius would offer him up as a sacrifice to save his own skin.
Draco Malfoy hated his father, and he hated being compared to him even more. So, when he was presented with an opportunity to prove himself, he jumped at it. Draco Malfoy wasn't a coward; he wasn't Lucius. He could do it. He could kill Dumbledore. He wouldn't even flinch.
He should have thought it through. He should have examined what he was being asked to do more closely before agreeing to it. He should have known that he would never be able to kill someone. Draco realized this soon enough, and it made him panic. Did not wanting to kill Dumbledore make him a coward, just like his father? That thought only made him panic more, and the fear brought him to do foolish, foolish things. Bewitching Katie Bell, poisoning mead; in his heart, Draco had known neither attempt would succeed. There was almost a cruel irony to the fact that Potter had been the main reason that they didn't; like the world was telling him he'd be better off following in Potter's footsteps than in his own father's.
Deeper in his heart than Draco liked to venture, he knew that he probably would be. But he could never do that. A Malfoy, on the side of good? It was unheard of. Worse, he'd never live to be remembered for it. If he tried to leave, he'd end up dead within a day. If he didn't complete this task, he'd be dead before he even got the chance.
"The boy's weak, just like his father. He can't do it. He's a coward."
He'd heard them sneering it behind him that night, as he pointed his wand at Dumbledore, and silent tears of defeat had escaped him. Anyone else would have thought he was crying from fear and inner conflict about what he was being pushed to do, but he wasn't. He just couldn't take it anymore. The entire year, he'd been spiraling; listening to person after person compare him to Lucius, call him a coward or weak or pathetic, and this was his breaking point. He just couldn't do it.
Draco never even considered that maybe he was listening to all the wrong people's judgement.