That certainly is a fringe benefit for Democrats (though I don’t know which is the prime objective - your theory or mine); the impact of these invaders would be negligible of the conservative states would just produce another generation of Americans in the WASP tradition.
Truly, this is one thing that we can control. We were encouraged to have just two children in the 1970s it is time to reverse that trend. Three children is the new two. Have as many as you can afford and look at your spending habits. How big a house do you really need? How many costly vacations must you take? Children are the real wealth. They will be with you for your whole life and they will give you grandchildren.