I guess what could be done in that direction would be this: allow immigration into the USA by the dregs of international society, namely: the idle rich, corrupt crime bosses and their helpers, criminals and malcontents, etc.

This has actually been done at times, specially with regard to Cuban expatriates (although I would certainly not want to tar all Cuban exiles with that brush!). Ever seen the movie "Scarface"? A very significant criminal element departed Cuba in the 60's and settled in Florida. Florida now has an extraordinary crime rate, while Cuba has a very low one. I was there. I saw how safe and friendly the streets are at night in Cardenas. I was also in Trinidad...which is not socialist. If you're smart you do NOT go out after dark much in Trinidad. It has a tremendous violent crime rate. It also has a lot more cops on the street than in Cuba...and the cops are notoriously corrupt and untrustworthy themselves. People avoid them.

Odd, isn't it? :-) Looks like providing people with a relatively good social safety net is a good idea. Poverty, gross material inequality, and social desperation are the wellsprings of crime in the streets...whether in Florida or in Trinidad.