The really big bucks go, not to the towboat operators who push fleets of barges on the Mississippi, but to the pilots who board oceangoing ships and guide them in the river. There are three state-licensed unions, each with its own exclusive franchise. One from to the open water to above "head of passes", one from there to New Orleans, and one from there to Baton Rouge. They get well over $300k per year, because the state legislators (to whom the unions give massive campaign contributions), require foreign-flagged ships to use them. Getting into the union requires family or "political" connections. New members give the union an initiation fee of about $250k, via a loan which they pay back out of earnings. Needless to say, this funds a massive PAC. U.S.-flagged vessels can use much cheaper federally-licensed pilots, although both groups must pass the same Coast Guard exams.

A very skillful group, both operationally and politically.