(Episode: "Trash of the Titans")
Now, "The Simpsons" is a smarter show than most people realize, and a lot of the lines are awkward to translate. The Spanish translators (who I presume to be Mexicans) quite often change lines for this reason.
Here is Homer's campaign speech, in English (found here):
Homer: Fellow citizens! How would you rate the trash service in this town?
Man #1: I would deem it excellent.
Homer: Uh, okay. It's excellent. But aren't you tired of waking up early and dragging the garbage to the curb? [Crowd Murmuring]
Man #2: That's so annoying in the morning.
Homer: Aren't you tired of having to peel that last snotty Kleenex from the bottom of your wastebasket?
Man #3 [with a huge nose]: I'll say.
Homer: Well, then -- Can't someone ELSE do it?
Crowd: Yeah! -- Yeah!
Homer: And can't someone else scoop out that nasty kitty litter?
[Crowd All Shouting In Agreement] Yeah!
Homer: Well, Ray Patterson thinks YOU should do it. Animals are crapping in our houses, and we're picking it up.
Did we lose a war? That's not America. That's not even Mexico!
[Crowd Shouting Excitedly]
Homer: Hemos perdido la guerra? Asi no es mi pais. Asi es el vecino del sur!
This a big change in meaning. The new line is much more (and directly) insulting to Mexico! What a strange choice.