How we cite our quotes: All quotations are from Taxi Driver.
Quote #1
PASSENGER: I'm gonna kill her. What do you think of that? Hmm? I said "What do you think of that?" Don't answer. You don't have to answer everything. I'm gonna kill her. I'm gonna kill her with a .44 Magnum pistol. I have a .44 Magnum pistol. I'm gonna kill her with that gun. Did you ever see what a .44 Magnum pistol can do to a woman's face? I mean it'll f***in' destroy it. Just blow her right apart.
This disturbs Travis, but it also presages his own rage. The passenger might not actually kill his wife, and this might be just a violent fantasy, but it's still disorienting. Travis isn't mad about adultery, but he is mad at a woman and he does have murderous impulses—and that might be why this encounter affects him so much. He senses a bit of himself in the sick passenger.
Quote #2
TRAVIS: Some fleet driver for Bell just got cut up. Just heard it on the radio.
DOUGH BOY: Stick-up?
TRAVIS: No, just some crazy f***er. Cut half his ear off.
This highlights how dangerous Travis' job really is. Like the other cab drivers, he could fall victim to the full nihilistic rage of the city, and can get killed at random. It helps us understand his own negative feelings more clearly.
Quote #3
DOUGH BOY: You run all over town, don't you?
TRAVIS: Yeah.
DOUGH BOY: You handle some pretty tough customers, huh?
TRAVIS: Yeah, I have.
DOUGH BOY: You carry a piece? You need one? If you ever need one, I know a fellow that can get you a real nice deal.
WIZARD: I never use mine. I'm conservative. But it's a good thing to have just as a threat.
This is ironic, because Travis will take their advice, but he won't get the guns for self-protection. He'll actually plan the harm of innocent people, like Charles Palantine.