The Center for Responsive Politics reports today that the average cost of winning a House race in 2008 was $1.1 million. And that $1 million, more often than not, decided who was going to be victories on Tuesday.
According to CRP:
In 93 percent of House of Representatives races and 94 percent of Senate races that had been decided by mid-day Nov. 5, the candidate who spent the most money ended up winning, according to a post-election analysis by the nonpartisan Center for Responsive Politics.
These numbers are basically unchanged from 2006, when winning candidates in 94 percent of House races went to the biggest spender. Senate races also tend to go to the highest bidder, with 88 percent in 2004 and 78 percent in 2006.