...Some worry that they will create their own tight community and will introduce division between communities.
From my observations, immigrants/refugees always have an ethnic enclave for the purpose of having a place to buy the food they like, and associate with people that speak their language, etc.
But, the children go to American schools, and adopt much of the American ways. By the grandchildren's generation, there is movement out of the enclave, and into other parts.
Not everyone is a model citizen. But, who knows if the descendant of some refugee won't cure a disease, or make some other worthwhile contribution to the society?
In my opinion, as I've been told, every barrel of apples has a few rotten apples. But most apples are good. From the very inception of this country that has been the paradigm for filling up this big country. And, since we have computers, it might be easier today to manage pro-actively that refugees are availing themselves of opportunity in the country. Where would many food franchises be without immigrant families to work long hours?