Yeah this really makes no sense. Outsourcing could've contributed over the last 10-20 years as globalization has happened but we're talking over 60 years of decline. And the government management team has probably been Democrats a majority of the time. To blame Republican businessmen for Democrat public management is just a red herring argument to deflect the problem.

The real issue are the natural human tendencies of white flight and minimizing labor costs and taxes. Most white middle class folks headed out to the burbs looking to maintain the standard of living while low income minorities entered employment areas looking for a piece of the pie. House values declined and crime increased as cultures clashed and jobs were insufficient for middle class and low income populations. Hence population declined and so did the actual tax base. Only the low income welfare folks were left behind as they couldn't afford to pack up and follow the jobs. Politicians made their careers catering to these constituents. The system fed off itself into decline

Likewise, incomes rose significantly while regulations and tarrifs declined to open up foreign trade and cheap labor markets. The blue collar middle class jobs headed out of town and state while the white collar middle income jobs stayed fixed in the burbs. More industrial tax base and jobs gone. But really where is the incentive for a blue collar job to stay in Detroit? What sense is there to pay 30 dollars an hour medical and retirement benefits to press a button and stamp parts all day? You can have uneducated foreign labor do the same "skilled labor" for $4 a day. Our labor market has artificially ballooned so much via union practices that it just doesn't stand up to common sense anymore. People have the right to TRY to maximize their standard of living but they have no guarantee to it. They quite literally collectively bargained themselves to the unemployment line without realizing it.