This is already the case in Europe though; if anything, the racism/discrimination situation seems better than the US, since you don't have to fear for your life if you're black and see a cop.
I'm not sure there is a "nice" solution when some people immigrate for the sole reason of freeloading on the welfare system. I've noticed that in France where some people do not even wish to integrate (the tools are there if you want it), and prefer to stay within their community, relying either on welfare, or will often transition to living off crime (drugs, etc).