CBS News chief investigative correspondent Armen Keteyian reports that because of a Supreme Court ruling earlier this year, you may never who's behind most of those ads.
Airing now is the first wave of an oncoming flood of campaign ads paid for by groups that don't have to tell you where their money is coming from.
One ad states, "Harry Reid says no one can do more than he can."
"She voted for special interest earmarks," is the claim in an ad attacking Sen. Patty Murray, D-Wash., by a group called "The Committee for Truth in Politics."
Despite its name, the Committee for Truth in Politics has no website, no street address, not even a phone number, and insists on keeping its donor list secret. It's all legal.
"The information about who is bankrolling an ad really is important, critical information," says Committee for Responsive Politics executive director Sheila Krumholz.
The closest one can get to "the truth" is the attorney who represents it, James Bopp Jr., a small-town Indiana lawyer who has become the go-to guy when it comes to fighting campaign finance disclosure.
CBS News had a conversation with Bopp about the Committee for Truth in Politics:
Armen Keteyian: "What can you tell me about the Committee for Truth in Politics?"
James Bopp: "I can tell you what is public record."
Keteyian: "Can you tell me how many members are on that committee?"
Keteyian: "Could you tell me how I can become a member?"
Bopp: "I don't know. I don't think you could."
Keteyian: "Could you tell me who your donors are?"
Bopp: "Oh, of course not."
The 58-year-old Bopp was the legal force behind landmark Supreme Court ruling in January 2010 that for the first time gave corporations, unions and certain non-profits the right to pump money into ads that directly endorse or attack a candidate, right through Election Day, without always disclosing who's paying for them.
Keteyian asked, "Jim, do you find it ironic at all that the word 'truth' is used but the committee is less than open about the truth about who is behind the organization?"
Bopp replied, "The truth has to do with the message. They haven't lied about who is behind it. They just haven't told you."
According to a new report from Public Citizen, only 32 percent of the outside groups spending on ads are disclosing who bankrolls their operation, down from nearly 50 percent in 2008. Many of these so-called shadow groups boast upbeat, bipartisan names like "Americans for Prosperity" and "American Future Fund."
"This is just the start. If you think it's bad in 2010, just wait for 2012 because this is just a test ground," said Krumholtz.
An ad by Americans United for Change states, "Hands off our Social Security and Medicare." The Democratic group, tied to organized labor, has already spent $4 million this year. They, too, refuse to release their donor list.
Early returns show groups supporting Republicans outspending those supporting Democrats by a wide margin. By August and early September alone it was $14 million to $2.8 million just for congressional TV ads.
There is a feast of new ads leaving the voting public to wonder who is really stirring the pot.