The Democrat socialist malaise was the SECONDARY infection.
Not exonerating the lefty Republicans from their responsibility. My recent reading of early 1900 US history shows globalism belonged in both parties. The average citizen did not want to be entangled in international issues even then. WWI and WW2 greatly advanced US globalism. That being said, the decay and fleeing of inner cities and empty store fronts started to occur well before the 1980s commercial globalism acceleration, and it wasn’t the average GOP politician running those places.