First of all, here is Louis CK on anti-Mexican sentiment in Arizona. (If you want to skip other parts, go straight to 7:40 mark.)
Although the entire episode is amusing, the punchline from the racist lady is what interested the Korean: "It's not that I don't like Mexicans, it's just that there are so many of them."
It is the Korean's steadfast belief that America is the least racist country in the world. As the Korean explained in the previous post, this is not to say America does not have racism, nor is it to say that America's racism is inoffensive. In fact, it is fair to say that America is the most race-conscious country in the world. In virtually any social context, the racial aspect of a given circumstance is never very far away in the minds of Americans. Why? It is not possible for any American to be unaware of racial aspects of her society because America has so many racial minorities.
The punchline from Louis CK is a perfect example of that. The racist woman in Arizona who gave Louis CK a ride would probably not display any overtly racist attitude toward, say, Indonesians. Why would she? Indonesians are not numerous enough in America to threaten her lifestyle with Indonesian language instruction being available along with English instruction at the parking lot she visits. But you can be sure that the woman will be just as racist toward Indonesians if America had as many Indonesians as it does Mexicans. The reason why the lady hates Mexicans (despite her protestations) is precisely because there are so many Mexicans in America, and Mexicans, through their numbers, threaten to displace her dominant place in the society.
As the Korean wrote in the previous post, it is meaningless to discuss whether a certain society is racist when the said society is devoid of a massive number of visible racial minorities. Such country may not appear racist, but that is not because the denizens of that country lack the seed of racist hatred in their minds. Unless faced with a situation in which their dominant social station is threatened by racial minorities, the seeds of racism do not germinate. America is the least racist country in the world precisely because America has so many racial minorities, precisely because Americans face the most temptation to be racist. Although the situation is far, FAR from perfect, it is to America's credit that most Americans resist the urge, denounce racism and bring about quick social death to their fellow Americans who even hint toward racism.
Got a question or a comment for the Korean? Email away at firstname.lastname@example.org.