I gave a presentation on this very topic during my PhD. The thing is, it does not stop at just cheaper labor... There are a ton of incentives for companies to manufacture overseas, tax benefits, resourcefulness, geo-locations of partner facilities , vendors etc., licenses and certifications laws, manpower, availability of raw material, the list goes on and on
Steve Jobs point blank told President Obama, production of the iPhone IS NEVER coming back to the US.... No matter how bad anyone wants it to, it will never happen!
Motorola thought they could make it happen and assemble their devices in Texas... Well, that didn't last very long:
http://www.engadget.com/2014/05/30/motorola-texas-plant-shutdown/The foundation for manufacturing in the US is just not structurally fit, it would take some truly radical changes to even make it a thought, but we are so far far away.