In Postville there has been residential segregation between the Postville citizens and the Hispanics who had just arrived. Apparently the citizens are upset by the sudden barrioization in the neighborhoods. They rose the real estate hoping that the new immigrants won't be able to afford the houses.
While there has been racism towards the Jews for not doing what the average Postville citizen does, it's a lot worse for the Mexicans. The police have been more alert since they have come, their "gangs" on the streets worry the people of Postville. Another reason for their dislike towards the Mexicans is that Saturday night service at church has been changed from English to Spanish. They most likely don't remember when there was a time in Postville that church was in German and then changed to English.
There were some cultural barriers between the Jews, Hispanics, and Postville citizens. Between the Hispanics and the Postville citizens there was definetly a language barrier, the Hispanics mostly spoke Spanish and the Postville people spoke English. Since the Hispanics spoke Spanish the kids had to learn English at school, and for some reason this annoyed the Postville citizens. Between the Jews, Hispanics and the Postville citizens, they just had different customs. For example the Jews ate pork and Postville loved it. The Jews had lawn that weren't expertly cut like the average Postville citizen because they didn't have much extra time on their hands. The Mexicans spoke Spanish, Postville didn't. The Mexicans hung out in groups on corners and the Postville people hung out in restaurants. The Mexicans and Jews seemed to get over the differences but others did not.
The people of Postville were used to folk culture, so everyone knew each other and things didn't really change. However since the Jews were from urban areas they had pop culture so things were always changing and busy. This bothered the Postville citizens because they thought if you came to Postville you should act like they do; the Jews weren't used to this because in NYC not everybody was the same and it was ok. When the Postville citizens were being rude/unfriendly to the Mexicans they were genuinely confused on why they were being treated differently. They understood that not everyone was the same but should all be treated the same, unlike the Postiville people.
The menorah is a part of Jewish culture.
The celebration of Cinco De Mayo, is a part of Mexican culture.
...more of Cinco De Mayo
Contagious Diffusion (relocation)
The Mexicans and Jews relocated to Postville. This is a type of contagious diffusion (where nearly all individuals/places are affected). This effected the people of Postville because things changed in their town. They had to change things they sold in stores, and even the Saturday night church service to Spanish for the Mexicans. They also had to respect the Jews wishes for not eating pork. These things had to be done to accommodate the new citizens, which I believe is fair. It's fair because just because you were technically there first doesn't mean you own the place.
Contagious diffusion is basically cause and effect. The cause in this situation is the Mexicans and Jews coming to Postville. The effect is all the Postville citizens are mad about it.