2. In William Faulkner's book, The Reivers, a mud farmer is somebody who pours water over roads so that cars would get stuck. They then charge to tow the cars. This is an allusion to politics and how politicians will scheme in ways to create revenue from extortion.
Greyfox: STFU you dumb mud farmer.
The IRS is a mudfarming organization. If you don't pay their extortion money you will be stuck in jail.