How successful have conservatives been in achieving their goals of defending "American" culture against an influx of immigrants in the 21st Century?

Not very successful

Explanation:

The 21st century has in fact seen the highest influx of immigrants in the United States of America with the American culture changing and evolving based on the diverse cultures and religions of immigrants that have come to become Americans. However, the core American culture remains the foundation of these other cultures- freedom of speech, freedom of religion, human rights, political correctness, and healthy competition are some of the practices that's still a solid part of the American culture.

a standing committee

explanation:

the caste system in india is the paradigmatic ethnographic example of caste. it has origins in ancient india, and was transformed by various ruling elites in medieval, early-modern, and modern india, especially the mughal empire and the british raj.it is today the basis of educational and job reservations in india.it consists of two different concepts, varna and jati, which may be regarded as different levels of analysis of this system.

the caste system as it exists today is thought to be the result of developments during the collapse of the mughal era and the british colonial regime in india. the collapse of the mughal era saw the rise of powerful men who associated themselves with kings, priests and ascetics, affirming the regal and martial form of the caste ideal, and it also reshaped many apparently casteless social groups into differentiated caste communities.the british raj furthered this development, making rigid caste organisation a central mechanism of administration

i didn’t fully understand your question but i hope this you !