I would guess this extends beyond immigrants at this point given all the data they have mined from the government

Legal immigrants commit crimes at a lower rate than U.S. citizens, and illegal immigrants at an even lower rate than legal immigrants[1]. This should not be surprising. Those who are in a country illegally know they will likely be deported if caught committing a crime.

Why build apparatus to monitor the people least likely to commit crimes? In isolation, it doesn't make sense. If you take a look at other actions the Trump is administration is taking, such as cracking down on universities in ways designed to suppress protest, it becomes a little more clear. This database will likely be extended to cover citizens as well as immigrants, and not for the purpose of preventing crime.

So the thing the traditional conservatives was most concerned about - deep state surveillance - is what they end up with. It's not exactly their fault or the Democrats. Both parties failed in leadership to prevent this.