From Open Secrets:
Except for a few late salvos in Louisiana, most of the 2014 cycle’s record-breaking outside spending is in the books. With no presidential election competing for resources, spending on this year’s congressional races rang in at $786 million, handily topping the $675 million spent on House and Senate contests in 2012.
The spending patterns took some different turns, though.
First, much more money was spent early in the 2014 cycle than in 2012. While the early 2012 cycle was consumed by the Republican presidential primary, 2014 saw a number of Senate primary battles. Led by the bruising GOP contests in Mississippi ($11.6 million spent on the primary) and Georgia ($7 million), 2014′s primaries were the target of $75.5 million in outside money, nearly 40 percent more than 2012′s $54 million.
The combination of contested primaries and special elections made this cycle’s off-year much more interesting. Due mostly to the New Jersey and Massachusetts Senate special elections, 2013 saw $25.3 million in outside spending against just $7.6 million in 2011. From February through June of the election year, 2014′s monthly outside spending totals were at least double 2012′s; the gap would likely be even bigger if undisclosed spending were taken into account, since groups like Americans for Prosperity spent millions targeting vulnerable senators with early-cycle “issue ads” that don’t have to be reported to the Federal Election Commission. In 2012, some of the difference was made up in October and November, when groups started to lay out real money: $435.6 million in 2012, $400.3 million in 2014.
Though Democrats made noise early in the cycle about building on their 2012 gains in the House, both parties quickly realized that the Senate was 2014′s only real prize. Outside spending on House races actually decreased 13 percent from 2012 to 2014, while Senate spending grew more than 40 percent, crossing the $500 million threshold on Election Day. This number is even more impressive given that 2014′s Senate races were concentrated in smaller (and therefore cheaper) states such as Alaska, Iowa, and Arkansas. A small number of those states received most of the attention: The top 10 races of 2014 absorbed 55.2 percent of the cycle’s congressional outside spending, versus 42.5 percent in 2012.
Though outside spending produced mixed results on Election Day, it did achieve one breakthrough. Unlike in 2012, the majority of outside money spent on congressional elections (56.1 percent) was “successful” in that it either supported an eventual winner or opposed a loser. This reflects the fact that conservatives, who outspent liberals in both cycles, had a very good year in 2014 and a very bad year in 2012. Thus, while post mortems of the 2012 election emphasized the low success rate of conservative super PACs such as American Crossroads, it’s now Senate Majority PAC‘s turn to hang its head.