Post-vietnam war the US became a lot more conservative. 1980's saw "trickle down economics" (giving money to rich people would trickle down to everyone, seriously), increased mandatory jail times, three strikes laws, increased funding for war against drugs, white flight from the cities to gaited communities. A lot of these trends seem to be slowing or even reversing a bit, one can hope.
It is true that rich people tend to fund things like large businesses, which then pay middle-class workers. However, giving them free money gives them no reason to actually use that money to fund more businesses. Why invest when Uncle Sam gives you an allowance?
I do like the Basic Income Guarantee, but have yet to do any math on how efficient it is compared to the US's welfare system.
Ideally, the money would come in the form of a standardized cheque, to be handed out once a month to anybody who is 18 or older and can come to the local DMV and provide proof of citizenship. Unclaimed money goes toward funding the program, getting more workers into DMVs to handle traffic, and (again, ideally) could be sent to a charity of the recipient's choice.
In the 1960's, liberal Supreme Courts created lots of new rights for criminals and the accused. In the 1970's and 1980's, crime skyrocketed. It went up so much that even though by the 1990's the incarceration rate had quadrupled, the rise in incarceration did not even catch up with the rise in crime until 1998. On the back of that rise in crime, there was a corresponding hardening of the justice system. The war on drugs, elimination of parole, etc.
Crime has dropped dramatically since the peak in the mid-1990's. But that massive build-up of the justice system has persisted, and today the incarceration rate dramatically exceeds the crime rate. As the people who forget that New York City in the 1990's used to be Gotham City, and now only remember it as Disney Land, the political slur of "soft on crime" is going to lose some of its bite. We are seeing Obama talk about criminal justice reforms that say Bill Clinton in the 1990's never would have been able to talk about. I remember growing up in the 1990's, and all the advertisements and school assemblies about drugs--a prevailing attitude that can only be described as "hysterical." Remember Clinton having to say "I smoked but never inhaled?" Today, we're seeing legalization of marijuana all over the country. We're seeing a generation of future voters that will grow up hearing about Ferguson and Freddie Gray instead of how people high on crack cocaine are going around raping women in the inner city. That's going to change what kind of police conduct voters are willing to tolerate.
That time frame also matches the rise and fall for the use of leaded gasoline, which has been theorized to be the cause of the crime rate rise and fall. [1]
You seem to be suggesting that liberal Supreme Court rulings caused the crime wave, and conservative backlash in the justice system curbed it. The conservative backlash may have been triggered by the crime wave, but I don't think liberal rulings caused the crime wave. The recent swing back to the liberal side, with the political changes you mentioned, and no corresponding increase in crime, seems to bear that out.
I'm not saying liberal rulings caused the crime wave. I am saying that there was a trend towards a more humane justice system that was stopped dead in its tracks for a generation by the crime waves of that era. I mention the liberal rulings of the prior era to highlight how the court system is capable of moving forward toward justice when the political climate is amenable to such liberalization.