There is no "door" when all immigration has been cancelled. Trump cut and then halted ALL immigration during his term. The net result has been the worker shortages you're seeing everywhere, as well as much of the price inflation on the cost of food in the US.
During the pandemic, many people decided to take early retirement, or to change careers. The USA had 5 million job openings when Obama left office. More than 1 million mostly adults, 60% of whom are of working age have died. With Trump cutting immigration, legal or otherwise, there are now worker shortages across the country and 11 million job openings.
It certainly puts the lie to the Republican notion of "open borders" being the problem. The problem is the lack of a reasonable and/or efficient immigration policy.