Amtrak is embroiled in a fight that may have vast implications for the future of US rail service, including the billions of dollars devoted to it from the bipartisan infrastructure bill.

Amtrak, which typically speaks in a mild-mannered tone on social media, has reinvented itself as a flamethrower that's launching snarky missives at the freight railroad companies that it says are blocking passenger train travel on the Gulf Coast.

Amtrak trains outside the Northeast corridor generally run on tracks owned by freight railroads, sharing the tracks on an agreed upon schedule, though unexpected delays occur when the freight railroads deviate from the schedule and run their own trains hours ahead or behind schedule.