Corruption by another name is still corruption

If I pay a Congressman to do an "official act" such as introducing legislation, then the Congressman could go to jail. But, if I give money to a Congressman's campaign account and he introduces legislation that he claims he would have introduced anyway, he gets away scot free. In either case, the politician is corrupted, but the campaign finance system in the United States treats the second instance as entirely legal, as long as the FBI doesn't have a voice recording of the politician trading the campaign money for a favor (I'm looking at you Rod Blagojevich). If you don't believe these quid pro quo deals happen, then you just haven't been paying attention