Regardless of having unions the factories will always relocate to the cheaper workforce if the costs of transport is less then the labour cost margin. Big business does not care, it wants a ROI. And it will always be easier to electronically transfer funds then it will be to physically move labour.

If you don't want goods manufactured overseas start supporting your local economy and buy local.

Most of this goodwill stops the moment people figure out that means they have to spend more of their money and they then go and buy cheaper imports.