Outside groups spent more than $1 billion during the 2012 election, according to a report released last week by Public Citizen.  Public Citizen asserts that this record-setting figure exceeds the total spent by outside groups in the four previous election cycles combined.  Other key findings of the report include:

• In four of the top 10 most expensive Senate races in 2012 (Virginia, Wisconsin, Indiana, and Nevada), outside groups outspent the candidates.  In 2012, spending by outside groups in these 10 races was 10 times greater than on the 10 most expensive Senate races in 2006.
• Outside groups spent 84 percent as much as the national parties in 2012. In the four previous election cycles, outside groups never spent more than 32 percent as much as the national parties.
• The top three outside spenders in 2012—Restore Our Future Super PAC, American Crossroads Super PAC, and Crossroads GPS—spent more than all outside groups combined spent in 2010.

Public Citizen’s use of the 2006 cycle as a benchmark for comparing overall outside group spending in the top 10 Senate races is somewhat dubious since comparing a Presidential cycle with a non-Presidential cycle presents an apples and oranges problem.  Even so, the trends that Public Citizen highlights are significant.  Because campaign finance laws constrain how much candidates and national party committees can raise, outside groups likely will continue to play a significant role in future elections.  Outside groups may even exceed spending by candidates and party committees in the 2014 election cycle.