What effect does multiculturalism have on the policy and national identity of modern-day Western nations?

The assignment I’m requesting is a 20-page research paper for a class entitled, “Contemporary Political Theory”. I just had a bout of severe illness, and I’m really looking to make it through the end of the course, so help is certainly needed. The idea that I generated for the paper earlier on is the relationship between multiculturalism and the modern day society of Western nations. Specifically, I want to investigate the effect of multiculturalism (if any) on the policy and national identity of modern-day Western nations. Sources are required (as it is a research paper). However, we were not given any requirements for the amount of sources. We were not given any reference materials for the assignment (However, our class readings did bring up Will Kymlicka, “Multicultural Citizenship within Multination States,” Ethnicities 11 (2011) 281-302). The paper doesn’t need to take a position, but rather to evaluate whether Western nations are altered by the presence of multiple cultures and to what extent.