“Paid for by MoveOn Political Action” appears at the end of only one TV ad these days, but MoveOn.org is involved in more behind the scenes.

MoveOn, for example, gave $583,000 to bankroll Health Care for America Now’s recent ad hammering McCain’s health care policy.

MoveOn also gave $400,000 this month to Campaign Money Watch, which recently ran an ad against Senate Minority Leader Mitch McConnell and today has a new one taking on McCain. (Private equity billionaire Jerome Kohlberg, a long-time advocate for campaign finance reform, also pitched in $130,000.)

The new CMW ad, aimed at conservative viewers in Florida, Virginia and on national cable, spotlights McCain’s penchant for gambling and his contributions from the gambling industry. Here’s a Las Vegas Review-Journal story on the subject. The ad starts by comparing McCain to “celebrities” who “love to gamble” like Paris Hilton and Britney Spears. It’s a sarcastic allusion to a much-discussed McCain campaign ad comparing Obama to the pop stars.

It may seem a bit odd that an organization dedicated to the public financing of elections would go after McCain, the only candidate who actually decided to take public financing for his campaign. Obama’s explosive fundraising, meanwhile, is being blamed by some for the imminent demise of the system.

But David Donnelly, director of Campaign Money Watch, explained to us a while ago, “Our view is that the current system is broken. Candidates are going to fund their campaigns in whichever way they think will bring them to victory.” For Donnelly, the question is, “Which candidate has pledged to make fixing the presidential system a priority?” His answer: “Obama has.”

This originally appeared on The Secret Money Project Blog, a joint project of CIR and National Public Radio tracking the hidden cash in the 2008 election.

Will Evans is a senior reporter and producer for Reveal, covering labor and tech. His reporting has prompted government investigations, legislation, reforms and prosecutions. A series on working conditions at Amazon warehouses was a finalist for a Pulitzer Prize and won a Gerald Loeb Award. His work has also won multiple Investigative Reporters and Editors Awards, including for a series on safety problems at Tesla. Other investigations have exposed secret spying at Uber, illegal discrimination in the temp industry and rampant fraud in California's drug rehab system for the poor. Prior to joining The Center for Investigative Reporting in 2005, Evans was a reporter at The Sacramento Bee. He is based in Reveal's Emeryville, California, office.