Who are you referring to?
Have you been to these? I have, in states red and blue. It's rarely a rah rah. Instead, people have complaints about specific categories of crimes, usually ones relevant to the community. The question is less locking people up than catching them. Policing. Sentencing is a separate system from policing.
Again, not in reality. Absent unlimited resources, street-level police determine which crimes are "policed" based on the severity of associated punishments. Change the punishment for drug dealing from a prison sentence to a minor fine and police will all but stop hunting drug dealers. Start sentencing jaywalkers to prison time and you will see cops at every pedestrian crossing. Sentencing is the guide by which police determine which crimes the public most want to see policed.
Nope. The American justice system does not control itself. It is bound by laws and codes of practice dictated to it by outsiders, those good-idea people who's entire understanding of law comes from a highschool history or civics class they barely remember. It is as bad as it is because the general public honestly want it that way. Rough and violent justice is baked into American culture as much as guns and alcohol.
>>Part of that is education.
I agree, but it isn't the people in the system that need an education. It is the voting public outside who need the better understanding.