Citizens united ensured manufacturing cannot be done in America.
Citizens united said money is legitimate political power. Manufacturing in China is cheaper and therefore people who manufacture in China will have more profits. More profits is more legitimate political power. So manufacturing in China means you have more political power in the US.
Not just decisions about manufacturing, it's hard to see the Citizens United decision as anything other than a major step backwards in representation of the people by the people, I'm not a US resident but it saddens me to think of how it's eroded representation in the USA.
How the USA is ever going to fix that I don't know, the very things that might change it, are going to be fought against, with almost unlimited funds, by the same entities who benefit from the change staying in place.
Citizens united said money is legitimate political power. Manufacturing in China is cheaper and therefore people who manufacture in China will have more profits. More profits is more legitimate political power. So manufacturing in China means you have more political power in the US.