You may enjoy This American Life's episode on "Take the Money and Run for Office" [1]
> Dick Durbin: I think most Americans would be shocked-- not surprised, but shocked-- if they knew how much time a United States senator spends raising money. And how much time we spend talking about raising money, and thinking about raising money, and planning to raise money. And, you know, going off on little retreats and conjuring up new ideas on how to raise money. [2]
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> Barney Frank: If the voters have a position, the votes will kick money's rear end any time. I've never met a politician-- I've been in the legislative bodies for 40 years now-- who, choosing between a significant opinion in his or her district and a number of campaign contributors, doesn't go with the district. [2]
The point is, if they are voted out they lose their jobs and income, therefore they must listen to voters. I'm not saying I support super PACs or anything, but I find it comforting to know that if we come together on something then we do have a role in the democratic process that is stronger than money.
[1] http://www.thisamericanlife.org/radio-archives/episode/461/t...
[2] http://www.thisamericanlife.org/radio-archives/episode/461/t...