Who should be allowed to move to America?

The people that should be allowed to live here is the people that are coming here to America for a good cause. Like for Mexicans, African Americans and anyone who really are desperate. One main reason people should be coming to America because of food , government, sickness, and money problems or something similar to that. Some of the people that come here for bad reasons like bombings, terrorism , drugs or anything illegal or dangerous I would recommend you coming to America because there are a lot of good people and they are just trying to live a good life .