What about Nativism seems to be conflict with the fundamental beliefs of the U. S?

The old and the new came into sharp conflict in the 1920s. ... and the ways in which new scientific theories might challenge traditional Christian beliefs. ... To “preserve the ideal of American homogeneity”, the Emergency Immigration Act of 1921 ... To rural Americans, the ways of the city seemed sinful and extravagant.

Explanation:

since most of current immigration into the u.s., both legal and illegal, is coming from latin america. it would be very difficult to imagine or rationalize a country my fellow citizens are trying desperately to flee into, would pose a threat to my prosperity or freedom. since the u.s. has a long history of intervention, but no record of permanent occupation, i would not feel oppression is the main objective.  

the largest free trade nation, along with the largest gdp in the world wanting to expand it's economic policy on us, and including us, could only be positive. the u.s. government has no interest in, or way of simply forcing american culture on us. and has no track record of it. other nations that adopted american social culture, or "americanization" did so voluntarily, mainly through the choice of allowing american businesses and u.s. citizens to come into their nations, as free operatives.

lancelot said to the beautiful ellen i c u r a b u t l n (i see you are a beauty lancelot was the greatest and worst of the knights who became the king's champion and undertook quests in the king's name. he became the adulterous lover of queen guinevere, and they had a son named galahad.