We are talking about 128million non White Americans and that is not including white Latinos. Just to put it into context the Holocaust killed 6million Jews, the Partition of India moved 12-20million people and created a lot of suffering doing so and somewhat similar numbers in displaced people in Europe after WW2(moving borders and the like). Those are some of the darkest chapters of human history and this would be an order of magnitude large then those.

First of all, doing that would create a massive reaction. We are talking 38% of the US population being deported, so a civil war is very much an option.

The honest answer is that a lot of Americans are very well educated and rather rich. So if they would be allowed to leave, then they would be welcomed by other countries. However we are talking about numbers here, which would compeletly change the housing and job markets here. The locals will not like that and close their countries off. Still a good number would make it. At that point the US has two options: Wage a war to take some land for them or kill them. Taking land would lead to hatred of the Americans including the deported. We are also talking about a massive country here and probably a lot of death. Obviously killing everybody would be even worse. There is also the option of pushing them into say Alaska and make that independent. However that is unlikely.

The US economy would be absolutly destroyed by this. If you deport them quickly, it would lead to shortages. Most certainly shortage of workers, which would indeed push up wages. Housing would end up being cheap and people would move to the best cities of the country. On the international stage the US would be widely hated and probably be hit with sanctions(they deport a lot of people and that causes huge problems for other countries). So long term it might actually be good for white workers. However the rich would hate it, due to it destroying their cheap workforce. Short term the US would have massive shortages and suffer a lot.

Even just deporting a larger part of the non-white population would cause a lot of problems.