>>The US-VISIT system was authorized but never implemented in 1996. <<
I don’t know if the “US-VISIT” system would work, but it sounds like it’s on the books, which was my point. What we’ve been lacking is the will to do it, and as you pointed out, Bush43 was one of the worst for having that will...until Obama came along.
So we have the law, and we certainly have the technology. We just don’t have the executive will to put it all together.
One thing Obama’s accomplished, however. He’s shown just how much the executive can get done via executive orders. If that law is on the books, a determined President could probably do almost anything he wanted when implementing it, including sending the DOJ after those college administrators who keep losing track of their students.
You are correct about the political will, The technology exists. Sanctuary cities are a primary example of nullification without any consequences. Those of us who have been working on this issue for many years have been acutely aware of it. The fact that Trump was able to bring to the fore is great. But Congress has not passed a very good bill and Obama will veto it anyway. Nothing will be done.