How we cite our quotes: All quotations are from Taxi Driver.
Quote #1
TRAVIS: All the animals come out at night - whores, skunk pussies, buggers, queens, fairies, dopers, junkies, sick, venal. Someday a real rain will come and wash all this scum off the streets. I go all over. I take people to the Bronx, Brooklyn, I take 'em to Harlem. I don't care. Don't make no difference to me. It does to some. Some won't even take spooks. Don't make no difference to me.
Travis judges the people he sees on the streets and predicts apocalyptic vengeance against them. At the same time, he accepts everyone in his cab and isn't racist (in terms of who he'll pick up) like other cab drivers. He silently condemns, and hasn't moved to making himself the instrument of judgment and vengeance.
Quote #2
PALANTINE: What is the one thing about this country that bugs you the most?
TRAVIS: Well, I don't know. I don't follow political issues that closely, sir. I don't know.
PALANTINE: Oh, but there must be something.
TRAVIS: Well. Whatever it is, you should clean up this city here, because this city here is like an open sewer you know. It's full of filth and scum. And sometimes I can hardly take it. Whatever-whoever becomes the President should just [Travis honks the horn] really clean it up. You know what I mean? Sometimes I go out and I smell it, I get headaches it's so bad, you know...They just never go away you know...It's like...I think that the President should just clean up this whole mess here. You should just flush it right down the f***in' toilet."
Palantine probably wasn't expecting this kind of rage. He has faith in the people, but here, he's encountering someone whose inarticulate anger cries out for violence more than for political reform. Palantine handles it easily though.
Quote #3
TRAVIS: You're in a hell, and you're gonna die in hell like the rest of 'em! You're like the rest of 'em!
Travis claims Betsy is "like the rest of 'em!" because she, uh, didn't want to see a porn movie with him after having just met him. It goes to show how warped Travis' mind is—he's the one who was acting creepy and weird, yet he condemns Betsy for behaving in a completely sensible way, claiming she's just another one of the people who disgust him with their heartlessness and depravity.
Quote #4
TRAVIS: But you can't allow him to do the same to other girls. You can't allow him to do that. He is the lowest kind of person in the world. Somebody's got to do something to him. He's the scum of the earth. He's the worst s-s-sucking scum I have ever, ever seen. You know what he told me about you? He called you names. He called you a little piece of chicken.
We didn't actually hear Sport call her "a little piece of chicken" but we did hear him say way more graphic and demeaning things about her (in addition to calling her a "b****" to her face). Travis hates Sport because Sport represents everything he dislikes about New York—coldness, heartlessness, money-driven exploitation of the innocent. He's trying to get Iris to see this instead of buying Sport's illusions.
Quote #5
IRIS' FATHER: There is no way we can repay you for returning our Iris to us. We thought we had lost her, and now our lives are full again. Needless to say, you are something of a hero around this household. I'm sure you want to know about Iris. She's back in school and working hard. The transition has been very hard for her as you can well imagine. But we have taken steps to see she has never cause to run away again.
Travis, despite committing a murder, earns the gratitude of Iris' parents and of society as a whole. Despite condemning and hating society, judging it negatively, he somehow receives the positive judgment of society as a whole by mirroring its own secret rage.