They did something like this in Dominican Republic, then the military went around deporting many people. Show up at a door "oh your great grandmother came here illegally we are deporting her whole family tree" then take them leaving all their possesions, house, cars etc. No matter 3 generations were born in the country :)
For sure all the Europeans in the USA started off as non-citizens. Like at what point did Trump's family heritage become a US citizen?
Supreme Court hears arguments on Trump's order to end birthright citizenship - BBC News
The hearing will give a sense of how the justices are thinking about a case that could have a profound impact on Trump's powers.