I don't think you're appreciating the policy in its fullness. It's to apply economic and social pressures which make it "one child for Whitey, because he can't afford any more, or 'cause it's his right to choose" and plenty of children for the oppressed. Do the math. Some have--for example, it's been said that the greatest weapon against Israel is the Palestinian womb, that Muslim infiltration of Europe and the US is the way towards conquest, and don't get me started on Azatlan.
China does this already. Han Chinese get 1 kid in cities, 2 in rural if first is a boy. To mollify minorities, they’re allowed 2 with fines starting with the third kid.