The reason people and politicians complain about losing manufacturing jobs, is not because of efficiency, its about shipping jobs oversees. Yes, todays manufacturers are more efficient then in the past, so less are needed in proportion to the population, but many of those jobs are still oversea's or in mexico. Truth be told, it wasn't even a big deal before the recession, because most of America was employed, so no one cared. It actually increased the GDP of America. Today it is a big deal because there are literally over a million jobs overseas that are run by American companies, while millions of American's can't find jobs.
Please see the post by DSGE.
I find it hilarious when people use the term "shipping jobs overseas". Have you ever been to a port? I have, and I've never seen a container being exported that contained jobs, only ones that contained products. The term "shipping jobs overseas" is a neural linguistic term that really means nothing but seems to get people emotionally aroused.
I have to wonder if you are also upset that 70% of Toyota cars that are sold in the US are manufactured in the US? Does it upset you that those poor Japanese people had their jobs (to use your term) "shipped overseas" to the US? What about Nissan, Mercedes Benz, Hyundai, Siemens, Tesco, BMW? Or is this a one way street for you?
But I digress.
In some places in the world, human labor is still cheaper than technology. That is changing, and those people will lose their assembly line jobs at some point (think cheap labor in China). This notion that manufacturing jobs (assembly line) is supposed to be a boon to an economy is an old economic model. Technology is replacing it, just as technology allows us to produce so much more food with so much fewer labor. Clinging to an extinct model is not going to make things better. Again, I ask, name a politician that want's his child to grow up and have a manufacturing job.