"Well, not sure about unions, but regulations and our tax system would apply to any company doing business in the US."
Except that foreign-based corporations only pay US taxes on their US revenues, while US-based corporations pay taxes on their worldwide revenue.
True, but there are lots of ways to defer those taxes, and they get credit for income taxes they actually pay to non-US jurisdictions. The bottom line is that it ain't the US tax system that has brought about this state of affairs; it's the notion that it's OK to outsource just about anything. Let's hope this becomes a teachable moment.