You guys have it backwards for US politicians- unlike in Argentina, where you become a politician, and THEN you get rich, in the USA, it works the other way around- FIRST you have to be rich, then you buy a political office as a status symbol.
Its more like an Audi is here.
The main qualifier to be in Congress is you must be a millionaire.
It costs around $20 million to run for US Senate.
The rich guys dont get any bribes in the US- they PAY the bribes. Being a politician in the USA can certainly help get you a good no-work job afterwards, but you still have to be a millionaire first from something else to get in the door.
And, no, Bajo Cero, you do not "fill in afidavits" to pay taxes in the USA- taxes are automatically included in purchases, like IVA here, and no fancy forms of any kind are required to buy most anything there, except real estate. You can still walk into a car dealer with a brown paper sack full of hundred dollar bills, and drive off with a car.
One very big difference between the USA and Argentina, which tells you a lot about this subject- every cash register in Argentina has a special RS232 jack on it, which has a little sticker above it that says "Uso AFIP". I hate to tell you this, but nothing like this exists in the US.