It would seem that no one has a real clue about who all is in the United States, where they came from, where they are now and when they were to leave. I would also suspect that there is not one single federal government data base that could be relied upon to provide correct information.
I was in our post office last night dropping off some letters. They used to have a slot on the wall for misaddressed mail. Now they have a huge box on the floor which was overflowing.
I asked one of our state legislators if anyone in our local government verifies documents of Medicaid applicants, like calling the state which issued the birth certificate presented to verify that that person was born in the state shown on the document. His response “I really doubt it”.