This election season has seen voters bombarded with corporate-sponsored ads courtesy of the Supreme Court decision in the Citizens United vs. Federal Election Commission case, which eased restrictions on corporate political advertising.

Much of this electioneering has been financed by three organizations: Crossroads GPS, led by Karl Rove, former advisor to the Bush White House, who helped bring us a seven-year war over weapons of mass destruction that didn’t exist; American Action Network, led by, among others, Fred Maleck, an officer in Richard Nixon’s Committee to Reelect the President, which was behind the illegal actions that gave rise to the Watergate scandal; and the U.S. Chamber of Commerce.

But voters don’t know who really pays for the ads, because in many cases the donors have to append their names to them.

The Obama administration and many election-watching groups planned to get legislation passed that would at least deny anonymity to groups with newly enhanced powers to flood the airwaves with money. A law that would have done that—the DISCLOSE Act (H.R. 5175 and S. 3295)—passed the House in June. But it was stopped in the Senate by Republicans, including Massachusetts Senator Scott Brown. Brown, whose regular-guy image together with a wave of Wall Street money won him the seat freed by Ted Kennedy’s death, twice voted against the law that would have let the public know who was paying for the election season ads.

The anonymity of an ad should be a red light to voters because the absence of sponsor disclosure is a signal that somebody wants to launch a message from cover—very often somebody who wants to enlist the help of voters in working the law around to help themselves, not the voters.

Why should sponsors of political advertising be exempt from disclosure rules? Why would Republicans want to help them be exempt? It hasn’t always been that way. In the last mid-term election (2006), donors identified themselves in 97 percent of cases, according to the FEC. This year the figure is 32 percent.

It’s estimated that $300 million worth of advertising paid for by anonymous donors will go into electioneering ads in this midterm. By mid-October, media outlets in Seattle, for example, had reported receiving $3.1 million for such advertising.

Then there’s the matter of foreign contributions (not anonymous) that come through American subsidiaries of companies headquartered abroad. There are 130 such companies, mostly European, according to Opensecrets.org, which calculates that those firms’ political donations are totaling more than $12.6 million in this election cycle.