America itself brought in the <undesirable> people from the <bad> countries in Europe throughout the 1700s, 1800s and 1900s - Irish peasants, Jews, poor and uneducated Italians, Germans, Poles, Hungarians and Norwegians.

It turned out that those peoples, given opportunities and in a system with functioning institutions, actually weren't violent, stupid or culturally incompatible and in fact thrived, integrated, built communities, grew the economy and contributed to society.

Something for you to consider.