The numbers wouldn't change from the current 1.1 million a year, just the composition of the immigrants. They would be more skilled and we would not be bringing in aged parents and others who would be using the social safety net and burdening our medical system.
The overall numbers need to be reduced significantly. Tom Cotton's RAISE Act, would reduce numbers to 700K a year, but that is still far too many. We could have a moratorium or reduce the numbers to at least 300,000. Given births and deaths, that would cover replacement levels.
We have around 4 million intending immigrants at any one time waiting overseas for their turn to enter. They have completed all the paperwork, background checks, etc. We have different categories of immigrants and there are annual caps on most of them except for spouses and children of immigrants. There will always be more people who want to come here than places available, no matter what criteria we use to bring them in. The annual intake of immigrants must be reduced period.
If we go to a merit-based system, the educated immigrants will be less prone to vote Dem and probably increase the number of non-Hispanic whites as immigrants. Currently, individual countries have limits as to how many of their nationals we will admit. India has been lobbying hard to increase their numbers. We would be better off not having these country caps if we truly wanted a merit-based system.
My take is there are eight billion people in the world. Half would come here if they could. How many do you let in?
Start at 100k and only those who can help America, are well heeled, plan on living here and spending their money here,true residents,not the economic refugees we get now.