Samizdata had an intersting angle -- how the incumbents outspent the challangers and lost. Robert Clayton Dean says:

"So for whom are these facts inconvenient? Proponents of campaign finance reform, that's who. State controls on campaign finance are premised (or at least sold) on the idea that money distorts elections, that without state controls elections will be bought by the candidate with the most money, that the gentle hand of the state is needed to ensure a level playing field and a fair outcome."

http://www.samizdata.net/blog/archives/2006/05/inconvenient_fa.html