The US government has been incentivizing citizens and non citizens alike to have children for decades.
Its simply a matter of targeting the right citizens.
Chicago is not America but an independent City State
The non-citizens still see children as “normal” and even after bearing them have a better life than they would in their homelands; too many citizens view them as a hindrance and burden - and the legal system gives many men pause as well. Nobody wants to produce children just to have them live with an ex-wife and another guy.