Jobs to china didn’t start until the early 90s at the earliest. The chart clearly shows that factory jobs have been falling since the 30s due to improved efficiencies and technology. A robot welder produces more than a hand welder and multiple can be run with one person efficiently.
This is little different then the impact that technology and efficiency improvements of tractors, other equipment, fertilizer, and improved hybrid seeds caused to family farmers. In that case increased yields reduced prices for the commodities produced making it more difficult for small acreage to compete.
Sorry you are off by about a decade.
80’s.
We have been sending US jobs overseas for now 30 years.
Non-stop.