Dak
mentat
Because unless we are talking about US citizens in another country, the "in" is the fact that matters for reasons of national policy. The wellbeing of the existing citizenry and their descendents are the only legitimate interests of a nation/national government. And that goes for the US and other nations. The wellbeing of the citizenry of other countries are those countries' concern. This moral imperialism, if you will, sees the US as responsible for all other persons in the world. It's a sentiment which has buoyed military "adventurism", and also seeks to destroy the native citizenry with the import of more hungry mouths, teeming with diseases, and lacking basic literacy.
As the US has no magic dirt to solve these problems, their presence is a drain on resources produced by others and a depressing of markets they move into - illegally - which means that their intent is ill; they want what they have no right to. In the cases where illegals are not of the abject poor (like tech sector H1B overstays), they instead are part of a brain drain operation on countries which are trying to develop, and yet still depress respective markets. A single citizen has no right to determine what happens to the nation, but the nation does and in a republic or democracy this does involve the wishes of a plurality of the citizenry.
We already attempt to do that through the fractional reserve banking system, progressive taxation, transfer payments, federal and state grants, tax incentives, etc. Each of these creates different supply and demand pressures but rarely "neatly" as intended. Except maybe the banking system benefiting banks and bankers, primarily, and the state education system benefits the state.
