That's the goal. The Jones Act guarantees a lot of American jobs and those workers are expensive. This allows US port-to-port shipping at much lower prices.
Good for the bottom line, bad for the worker.
Specifically, the Jones Act guarantees trucking and freight rail jobs by making it unreasonable to transport goods by water.
> Good for the bottom line, bad for the worker
Bad for most workers. Good for a cabal. The Jones Act directly lead to the failure of American shipbuilding.
It destroys far more American jobs in favor of a special interest group.
Jones act also guarantee lack of competition between shipyards. When companies MUST buy from you, there is no pressure to improve and you can set prices as you like.
Now US shipbuilding has been shielded from competition for so long, that any kind of permanent repeal of Jones act will mean instant bankruptcy of US ship builders. Similar to what happened in Eastern Europe after 1989. That shock of not being shielded by iron curtain from competition has caused implosion of whole industries.