What's the ratio?
There was a story last week about a factory in China automating 60,000 jobs. Sure, you need people to oversee that - but it's a fraction of the jobs that were lost.
the ratio is too complex for me to calculate off hand as there are too many moving parts.
Lets say you bring back a widget factory. Fully automated.
Of course you need the people to maintain the robots, sanitation, white collar management work, and security as you mentioned. Those people now need to live in the community. They need to buy food, have people, to cut their hair, prostitutes to have sex with, and various other things. So the service industry in that community grows. Of course as more people produce in the local community the more jobs are created as well.
For the next part read up on the economic concept of "backward linkages". Say that for a widget to be produced you need the raw material wid and get. If the plant was in China the raw materials would likely be sourced in China as well. If in the US then in the US. The places that produce Wids and Gets would have more orders. This means they hire more people or if enough demand is there more sources of Wids and Gets open up. That then creates employment in those areas.
Of course you now need to transport the raw materials to the factories. Normally only the chinese transport sector would get these jobs or chinese truckers if you will. Now American truckers get these jobs. Given that these guys are very mobile they spread the economic stimulus around.
This is just form 1 automated factory. Imagine the multiplier effect for more. Liberals only see the specific tree and the specific area that a factory operates in, when in reality each factory you bring back , again even if fully automated, is another artery that pumps economic lifeblood to the country.
So my question is why are you ok giving up all these jobs?