Hey Xenophobes....
Boeing is pretty much only left in the business of designing and assembling kitsets these days - parts being complete assemblies, not nuts and bolts.
A good chunk of those parts are already built in China/Japan/EU under contract. On top of that both Boeing and Airbus have plans for complete assembly lines in China - right now those are in addition to US lines but I can easily see Spirit (The Kansas line) being completely shut down in favour of offshoring.
China produces a lot of cheap junk and a LOT more high quality product that costs more (but is still usually cheaper than western built stuff). You get what you pay for and must perform due diligence.
US and EU workers must accept that costs must decrease or face losing their jobs entirely. The halcyon days of 100% employment, retirement at 65 and affluent workers are all in the past - they were all unsustainable long-term and have been financed since the late 1960s by debt/ increasing taxation in order to keep voters happy. Now those chickens are coming home to roost
The RJ market is the best place to be for any manufacturer, else Bombardier/Embraer/etc would be producing larger aircraft. Larger jets give prestige but the market is relatively tiny and only companies with substantial government backing can afford the investment to design/build them. (Boeing and Airbus BOTH have this)
Like it or not, the USA is about to join the also-rans in the global economy. It's not as if there is a dearth of ex-superpowers in this position...