> I think a lot of good would come from that and not much bad.

Here something that'd happen - the homeless in encampments would get hoovered up by slumlords who put them in squalor and consume their $1k checks. Poor people would have more children because each child = $1k/mo, even if they have to wait 18 years. Abduction would be easy - the ransom pays itself over time. Fraud would be rampant. The ultra poor underclass who are undocumented would still get nothing, further exacerbating the divide.