Sunlight Foundation

In the two weeks since Election Day, Sunlight -- along with many others -- have examined the impact of outside money. In competitive House seats we found no statistically observable relationship between the outside spending and the likelihood of victory, and found no evidence of spending impacting outcomes for the Senate either. It's important to note that those who contributed to the $1.4 billion spent by outside groups still matters, though. As Executive Director Ellen Miller notes: "Even if their candidates lost, the influence bought by America's new class of mega donors will remain." Here, we find some indication that outside spending in primary races may have had implications for general election outcomes this cycle. In the competitive races where there was significant primary activity by outside spenders, as compared to a baseline in which parties retaining control of seats they held in the 112th Congress, Democrats over-performed while Republicans significantly underperformed. Furthermore, we found notable involvement by outside Democratic groups in Republican primaries which may have played a roll, while finding little evidence of parallel Republican activity. We looked at the 90 races in the House that were competitive as of September 6th, according to the Cook Political Report (Likely, Lean or Tossup). Of these competitive seats, in the 19 where there was more than $10,000 in outside Democratic spending, Democrats won 17, a success rate of 89%. This was despite the fact that 12 of those 19 seats were previously held by Republicans. In contrast, of the 25 seats where there was over $10,000 in outside Republican spending, Republicans only won 11, or 44%. 17 of these seats had been held by Republicans prior to the election.