THE FUNDING BEHIND CAMPAIGN SPENDING
Since Citizens United, spending by super PACs and dark money groups, along with non-party independent groups, has accounted for a larger proportion of total election-related spending with each midterm and presidential election.
Candidate and party spending, as a result, has declined as a share of the total. Like super PACs, political party committees may make independent expenditures. But they are hindered by contribution limits and cannot take money from corporations or unions.
The balance of political power shifted from political parties to outside groups that can spend unlimited sums to bolster their preferred candidates. Election-related spending from non-party independent groups ballooned to $4.5 billion over the decade. It totaled just $750 million over the two decades prior.
In some of the most competitive races, outside groups wage ad wars of their own, battling for spending superiority to influence voters. Since the 2010 midterms, outside spending has surpassed candidate spending in 126 congressional races.