SOCIO ECONOMIC TENSIONS IN IOWA?

Since moving to Sioux City (a small agricultural and retail based city in western iowa with a pop about 80000) I have noticed there is a lot of socio-economic tensions between cles. The economy here is based on agriculture, medical, retail, and restraunts. The tension is mostly between the middle cl (both upper and lower) and working cl. Almost to the point of hatred on both ends. I have never seen been exposed to something like this. I grew up in a working cl family in Chicago and we did have this type of socio-economic tensions, at least not in my neighborhood. In Chicago, it was usually racial or cultural tensions, not cl. Why is there so much cl prejudice in Sioux City?