Every single year someone in congress puts user fees back into a bill in Congress
and every year AOPA, NBAA etc fight to have it removed or prevent it passing.
This is despite a funding bill which will cover the FAA costs for multiple years being passed every so many years. The aviation trust fund is where the money comes from.
AOPA USA is a BRILLIANT ORGANIZATION by the way with over 400,000 members ( that's a lot of political clout/votes ) and a lot of great services of all descriptions for pilots. Anyone flying in the USA should join up.
Many members of Congress are GA pilots too which helps the cause fight this user fees rubbish.
They have a legislative team in DC that watches out for all aviation related legislation that lawmakers try to sneak through etc. usually by attaching to a bill that has absolutely nothing to do with aviation.
User Fees should NEVER have been voted in here in Aust.
All aviation services should have been funded by the fuel taxes as mentioned above with any shortfall made up from general revenue.
After all, aviation is an essential part of the nations transport infrastructure like roads and railways. Apart from the odd toll on some bridges and tollways in the East we dont pay a per /Km user fee to drive on the nations roads.