About $97 million was spent by outside groups on media buys categorized as primary spending for the mid-term elections, according to Sunlight Foundation analysis of Federal Election Commission data. Of the $95 million in spending where party identification could be determined, Republican-leading groups outspent Democrats $59 million to $36 million.
But Democrats were the big spenders on attack ads, which Sunlight suggests is an effort to soften up the candidates for November, so general election-targeted spending classified as primary spending.
The top spender on ads and related ad production and ad buyer expenses was the Senate Majority PAC at $13,021,696, with all but about $2 million of that spent on ads opposing Republicans.
The U.S. Chamber of Commerce spent $11,580,732 at number two, with almost $10 million of that supporting Republicans, another $762,5000 spent opposing Democrats, and $1 million opposing Republicans.
Club for Growth Action was at number three, spending $6,240,774, with $4,678,119 spent opposing Republicans.
Democrat groups spent almost $28 million opposing Republicans, while Republican-supporting groups spent only about $2.5 million opposing Democrats.
But the caveat is that these figures don't include the dark money "issue ads" that aren't reported to the Federal Election Commission. Those are ads that don't expressly attack or support a specific candidate. Sunlight says that Republican-backing Americans For Prosperity has spent eight figures attacking democrats in unreported spending.
Sunlight tracks those expenditures using the FCC's online database of TV station political ad files as well as paper files from the stations. Big Four network affiliates in the top 50 markets have had to post their political files online for the last couple of years, but the requirement did not extend to all stations until July 1 of this year. Cable political advertising does not have to be posted in the database, though the FCC is looking to extend the requirement to cable, satellite and radio.