$564 million was spent by outside interests to influence the outcome of the 2014 midterm elections. Did that money make any difference? According to an analysis published yesterday by the University of Virginia Center for Politics, the answer is no.

In “Why Outside Spending is Overrated,” political scientist Alan Abramowitz (Emory University) performed a regression analysis of the 2014 Senate races. He considered four independent variables for each state race: the difference in outside spending for the Democratic and Republican candidate, the difference in party spending for their candidates, incumbency, and President Obama’s vote tally in 2012.  His conclusion? “After controlling for state presidential partisanship and incumbency, relative spending by outside groups and political parties had no discernible impact on the Democratic candidate’s margin in these contests …  outside spending by conservative groups had little or nothing to do” with the GOP’s midterm victories.

So why did the GOP capture the Senate?

 The main reason why Republicans did very well in 2014 was that Democrats were defending far more seats than Republicans and many of those seats were in states that normally favor Republicans based on recent presidential voting patterns. Democrats lost all seven of their seats in states carried by Mitt Romney in 2012 even though Democratic candidates enjoyed an advantage in outside spending in several of those races.

Here, Prof. Abramowitz and I agree.  And he doubts that the story will be any different in 2016:

The factors that limited the impact of outside spending in 2014 are very likely to be present in the 2016 elections as well. In the large majority of states, the winners of the presidential and Senate elections will be determined by the relative strength of the parties in the state. In the last four presidential elections, 40 of the 50 states have supported the same party in each contest, and there is little reason to expect anything different in 2016. In the 2016 Senate elections, Democrats are likely to gain at least a few seats simply because Republicans will be defending a large number of seats in blue states that they picked up in the 2010 midterm election. Notwithstanding the plans of the Koch network to spend almost $900 million on the 2016 elections, neither party is likely to enjoy a substantial advantage in spending in the relatively small number of competitive states that will decide the presidential election or control of the Senate.

Libertarians who hope that right-of-center 527 “Super PACs” will be a vehicle to political power should take note.