Well since the 787 program will very likely never break even, let alone turn in profit, for Boeing, the 737's replacement will be a do or die project for Boeing. They cannot afford another money-losing product.
There are only two¹ major manufacturers of commercial airliners: one in the US and one in the EU. Both are essentially state backed. Both blocs want to have their own manufacturer, for strategic reasons, and they won't let it go under.
1. There will probably be three in a few years, since China is building up Comac.
seeing how much power shifted from legislative branch to executive, and how often executive branch changes its mind, I wouldn’t count on the unwavering government support
There are only two¹ major manufacturers of commercial airliners: one in the US and one in the EU. Both are essentially state backed. Both blocs want to have their own manufacturer, for strategic reasons, and they won't let it go under.
1. There will probably be three in a few years, since China is building up Comac.