Shankar Vedatam writes in the "Department of Human Behavior" feature in the Washington Post about what exactly campaign contributions buy you on Capitol Hill: he says it's not a matter of buying votes, but of "cutting in line" as it were when it comes to setting legislative priorities.
Vedatam cites this anecdote to illustrate the distinction:
[M]any years ago, [Richard] Hall came to Washington on a fellowship to work for then-Sen. Tom Daschle (D-S.D.). Hall and Daschle were fired up about a hunger relief bill that was working its way through Congress. It was not an issue that resonated with many of Daschle's constituents -- but it was an issue the senator cared about deeply, and Hall was enthusiastic to work on an issue that touched his conscience.
As Hall worked on amendments and helped deal with the minutiae of moving a bill through Congress, however, the outlines of a drought emerged in the eastern part of South Dakota. Daschle told Hall that they needed to do something to help the dairy farming industry. Hall put the hunger relief bill on hold and began working on a measure to help farmers.
By the time Hall finished his Washington fellowship, he had gotten a lot accomplished to help dairy farmers. But the hunger relief bill was still sitting on his desk.
The anecdote, says Hall -- now a prominent political scientist at the University of Michigan who has studied the role that money plays in politics -- is a perfect illustration of the real effect of campaign contributions and lobbying. Campaign contributions and lobbyists do not buy politicians' opinions as much as they buy their priorities.
Well, it may not seem as immediately corrupt but: hungry people are still going hungry. The fact that campaign cash may not immediately buy votes is hardly an impressive distinction when money directly influences what votes are had at all. There's some argument in the article as to whether this kind of thing can rightly be called "corruption" -- I'd say when money regularly changes the governing priorities of a legislative body by deciding whose needs will be responded too you've got clear corruption on your hands.