The political scientist will insist that there is no good evidence that money affects results directly. Despite generations of empirical work trying to show a quid pro quo, nothing has been found. Yet even without changing votes, the dynamic can skew Congress' work in predictable ways. This dynamic changes government. The work of Congress gets diverted. The issues that get attention are different from what they otherwise would have been. Think about Bill Gates' claim—"fifty times the amount spent on researching malaria goes to finding a cure for baldness"—and shift the reference to government: In 15 words, you have a picture of Congress.

"But is this really it?" you might ask. "That the dependency of private funding simply shifts the focus of Congress? That's all? And if so, is this really the issue to worry about?"

This is where I got stuck for most of the time that I've thought about this question. No doubt there's a theoretical harm here. But what's its practical effect? Why should a reformer worry about this before she worries about health care? How could a reformer justify working here when there are issues like global warming that need a solution too? One response would be to quibble with the scientists. For not everyone believes the story is this sanguine. Many former members of Congress, for example, are quite convinced that money has a significant effect, certainly on the agenda, but also on the results.

Many believe that money at least buys access. As Sen. Paul Simon put it, when you're handed a stack of telephone messages at the end of the day, most of which are from people you've never heard of, and one from someone who has given you $1,000, "which call do you think you're going to make?"