If they went out of their way to move here, we can reasonably assume they intend to stay here

Moving is hard, even between states. I know this from personal experience moving between states. Moving to an entirely new country has got to be harder, especially with all the legal hoops to jump through. If they went through the mess to get here, they must really want to be here. They want the United States to be their home, and a desire to partake in the American Dream should be respected. If they pay taxes, there's no question that they've invested in our country.