If the failure is severe enough, ultimately yes. There is only so much bailing out that a capitalist free market country can provide.
No doubt the US government will bail out Boeing at least once, but I would expect that to be it. A one last chance point of no return. If Boeing ever gets to that point and still fails further, the US will have no choice but to have them fail.
On the plus side, it's not like Boeing going under is an actual national security threat. There is nothing wrong with relying on Airbus who will no doubt move into the newly vacant market spaces, we are all NATO allies aren't we? To say nothing of Lockheed Martin and Northrop Grumman who do a better job of military aviation anyway.
I'm also not sure "we'll probably only bail you out once" is a great position to take in motivating Boeing and its ownership and governance to make major changes to survive as a company.
