most of the time breeders do not practice birth control or use abortion. what is coming across our border does not practice birth control.
The power obsessed may know what they want, but they aren't always rational about how they get it.
Of course, they never look at the flip side, i.e. that we are only 4% of the world's population and land area and product 50% of the world's corn, 70% of the world's durham wheat, etc. And it is about 1% subset of that 4%.