So how much can a curious person find out about the sources of all this money coursing into Senate and House races this year?
Specifically, what can you find out especially about the money from the often shadowy, ostensibly non-political groups behind the money?
NPR's Peter Overby and Andrea Seabrook decided to try to learn what they could. They traveled to Pittsburgh and visited some local TV stations.
You see, it appears the only way to find out what groups are buying TV ads and how much commercial time they're purchasing is to visit stations and eyeball the paperwork the broadcasters are required to make available to the public.
The need for such station visits is an obvious absurdity in the Internet age. If the data were placed in public databases or websites, Google could make all this information accessible instantly.
That would be if the true goal of the filing requirement were real transparency. But it isn't. The goal is actually more the appearance of transparency than the reality of it.
When they recently arrived in Pittsburgh, Andrea and Peter turned on their hotel TVs and started watching for the campaign ads, perhaps the only two people in the city at that moment who actually wanted to see as many of those ads as possible.
ANDREA: Each local station is airing twelve or fourteen ads per hour during the evening news.
PETER: These ads are not all the same. Some come from the candidates themselves. Others come from party committees — like the Democratic Senatorial Campaign Committee or the National Republican Senatorial Committee.
The ones we're interested in come from other groups.
ANDREA: Two of them advertising in Pittsburgh — Americans for Job Security and the U.S. Chamber of Commerce.
PETER: Here's what we know about these groups. They're both 501-Cs organized under the tax code as non-profits.
The law says they can't engage in politics as their primary purpose. The law also says they can accept unlimited donations and they don't have to report their donors.
ANDREA: Unlimited donations. From unreported donors.
PETER: Couple that with Citizens United, that decision from the Supreme Court last winter, and you have a wide open path for corporate money to flow into partisan politics.
ANDREA: That's what makes these ads different from those others. Candidates and party committees have legal limits on the size of donations they can take from each donor and they have to report the names and numbers — the donors and how much they gave. It gives context to the ad.
But these non-candidate, non-party, supposedly non-political groups, with these, there's almost no context. We have no idea how much they have or how much they're spending.
PETER: BUT even those groups do have to disclose something — not to the voters, but to the TV stations.
ANDREA: And whatever they disclose to the TV stations, the TV stations have to disclose to us, the public.
It's the only way to track down how many ads these groups are running and just how much they're spending.
(Peter and Andrea visit a TV station)
ANDREA: Now, Peter won't tell you this, so I will. Peter Overby has spent a career tracking down money in politics. He's an expert at this. Today he and I are going to dig in to the public filings at a couple of Pittsburgh TV stations. We head over to the first one, and I stop Peter in the parking lot.
PETER: We're at WTAE which is the ABC affiliate here in Pittsburgh. We're going to go in an look in the political file, which is the documentation of all the political advertising that they've sold for this election cycle.
ANDREA: What do you think you'll find?
PETER: Not sure. We'll definitely find records of who's been buying the ads, how much they've been paying for them and, in a very general way, why they say they're buying them.
ANDREA: Remember, these are public files. Anyone can look at them. A station employee, who asked not to be named, lugs the files into a conference room.
STATION WORKER: I'm not quite sure what you want to look at. I tried to separate it by candidate and issue-action committee, that kind of thing.
ANDREA: You're thinking along the same lines we are. So, here we go.
PETER: These are big files.And we find some big numbers. (sound of paper rustling.)
Take the U.S. Chamber of Commerce. It's one of the most powerful voices in these midterm elections. In period of three weeks WTAE logs 206 ads by the Chamber.Ads for the Senate race and two House races. The cost, $134,000.
ANDREA: That's for one station, in one market, in the chamber's nationwide campaign. We also come across many disclosure forms that give less than full disclosure. Peter points at a blank on the form.
PETER: They totally skipped that. ... It's not atypical. Unfortunately it's not atypical.
ANDREA: And when we visit another station, KDKA, we find more hudge ad buys,
PETER: For instance, you have Americans for Job Security. This thing shows on September 7th they booked basically a month's worth of ads, they paid $105,000.
ANDREA: And more incomplete paperwork.
PETER: You gotta fill in the name of the candidate that the ad is talking about here, and Americans for Job Security left it blank. Which is okay, except that the ads that they're running specifically mention candidates. They mention the Democratic incumbents that they're attacking.
ANDREA: Peter's looking at the standard filing for political ads — this one from Americans for Job Security.
The group is supposed to declare if the ad is talking about a national issue, and if it is, which candidates are named. Americans for Job Security left it blank. Here's the ad.
(Part of the ad is played) ... With Pelosi and Altmire's agenda, it can feel like you're getting robbed. This November, vote AGAINST Jason Altmire...
PETER: So the groups are filing their paperwork with stations but they're not taking it very seriously.
Some answer a few questions, most leave the important lines blank. It's an indication that TV stations can't act as a watchdog of these groups.
ANDREA: This is where the trail goes cold. We called some of the groups behind these ads. They either said they were busy, they're complying with the law, or they didn't call us back at all.
And they don't have to. For most of these groups there's almost nothing required in terms of donor disclosure. They can keep their funding sources comfortably hidden.
But from sifting through the public files at two Pittsburgh TV stations we did learn a few things.
PETER: We learned that these groups are spending amounts of money that were unimaginable just a few years ago. One group can easily spend $100,00 or more at one station, in a few weeks.
Multiply that by four or five local stations in each area, and five or six groups spending at that level, and the amount of money flowing from secret sources to fund attack ads across the nation is easily in the hundreds of millions of dollars.
ANDREA: In our two days in Pittsburgh, we saw ads attacking candidates of both parties. But the ones attacking Republicans were all from Democratic candidates or party committees — groups that have to disclose their donors.
We did not see one ad from the supposedly non-political groups that attacked a Republican. Here, those are all aimed at Democrats.
PETER: We know that this year, in the wake of Citizens United and other court decisions, corporations and rich donors can give as much cash as they like to these groups.
ANDREA: As for who they are exactly? THAT's what we don't know.
PETER: In our next report, we'll talk to a candidate being attacked and a campaign benefitting from those attack ads.
ANDREA: And we'll talk over what this all means with the people the groups are trying to sway — the voters.
PETER: That's in our next story, on All Things Considered tonight.