Earlier quoted context omitted.
That is the problem with protectionism. What starts with good intentions ends with a bandaid that someday will have to be ripped off at the cost of the people who made a subsidized living based on it.
Except if you can't move stuff around without support of 3rd party nations, that's defense crippling. If you want to be a global power, you require great navy, both civilian and military. That's been true since 1500s and will likely remain true for many years to come. So question is, do we throw out Jones Act and slowly stop being World Superpower or leave it and pay higher upfront costs in certain places? That's pol…
I'm not super sympathetic to arguments that presuppose the absolute requirement that US hegemony continue indefinitely, but certainly if you are trying to make sure your shipbuilders will be roughly as good as foreign ones or better (a reasonable policy goal, even leaving out military reasoning), cutting them off from competition with those foreign shipyards is not going to result in what you want. If there is a ready market for expensive, poor quality ships that take years longer to build than they do abroad, why would I as a shipbuilding executive invest to improve on any of those metrics? It would be wasted money, because my existing capital and workforce are already 100% utilized in high-margin activities, with orders stretching out years into the future.