From ~1950-1970, unions were powerful and they redistributed a lot of income from business owners to employees. Compared to today, there were a lot of high-pay

From ~1950-1970, unions were powerful and they redistributed a lot of income from business owners to employees. Compared to today, there were a lot of high-paying low-skill jobs available. After the US opened its borders to global trade -- in particular Nixon's famous visit to China -- the unions became less powerful and wages became lower because companies had to compete with overseas workers, who didn't have troublesome unions, didn't have to pay their workers well, didn't have to enforce good working conditions, didn't have to comply with environmental regulations, et cetera. In other words, the surplus that used to be captured by US workers has started to go either overseas or to business owners, thanks to our trade policies.