I have to use the words nativism and KKK in a sentence.
Although we usually think of the Ku Klux Klan as an anti-black organization, there was a time in history where their big thing was nativism.
This was in the 1920s and a bit before that. During that time, American culture was changing rapidly. Especially in the cities, new forms of entertainment were springing up, and people were having more leisure time. This led to a new culture with flappers and other such examples of a new morality.
The KKK and others blamed this new and (to them) immoral culture on the effects of the immigrants who had come since the 1880s. Therefore, the KKK came to have a slogan "100% Americanism" and to be mainly a nativist group.
Given this information, you should be able to use both words in a sentence.
If one wanted to pursue this in a larger conceptual scope, I think both terms can fit a greater configuration. Both Nativism and the Ku Klux Klan represent expressions that seek to embrace a singular and repressive notion of the good. In both modes of thought, one sees a reticence to embrace any divergence from the stated purpose of both movements. In Nativism, a disdain for those who come from different narrative experiences is articulated. Similarly, in the Ku Klux Klan, one notices an equal dislike for individuals whose narratives are not similar to the cultural majority. In both, we see the idea that the desire for an ideal setting and a pure quest for a singular expression of it help to permit repression and the silencing of voices.