Re: Someone explain to me...
There are 435 Representatives in Washington, each representing a certain chunk of the country. Each one gets directly elected by those constituents, and it's an election year, meaning ALL of them need to stump for their votes. Meanwhile, each district has their varying concerns on which their elections will pivot, so these Representatives ask their more influential friends to help. The basic formula went, "I'll help you get this done if you vote for the greater bill that enables everything."
The House tried to establish rules limiting this practice since other voters noted it to be an element of corruption, but they found it to be a necessary evil. Those lesser representatives had no motivation to vote for controversial bills otherwise, putting important bills in jeopardy and lowering Congress's approval rating as a whole due to a climate of nothing happening because of the lack of corruption (of course, this never influences the local elections much--there it's always Somebody Else's Problem).
You see, that's the thing about governing by committee like this. Each member has its own motivations and rarely do they honestly come together when the motion to be passed is a "necessary evil" one (structurally necessary but very unpopular--tax reforms, for example). About the only time they come together is when some kind of crisis (like 9/11) hits. 200+ years of experience seems to indicate this is just basic human condition at work. It's not something that can be easily solved which is why corruption tends to show up in ANY form of human government imaginable.