Earlier this year, FEC Commissioner Ann Ravel was so frustrated by the partisanship within the panel that she took to the op-ed pages of the New York Times to shake her fist at the way her Republican colleagues went out of their way to protect Karl Rove and his shady donors.

In frustration, Ravel invited the groups who brought the FEC complaint to sue them, writing that "unless Public Citizen and ProtectOurElections.org prevail in their lawsuit, there will be no inquiry, and Crossroads GPS will continue to spend millions of anonymous dollars to influence our elections."

Public Citizen and ProtectOurElections.org have now done just that. Last week both organizations along with two individual plaintiffs filed a lawsuit in federal court against the FEC, demanding that they pursue action against Crossroads GPS to force disclosure of their secret donors in compliance with federal election law and the principles of disclosure laid out in the Citizens United ruling by the United States Supreme Court.

There are no guarantees in courtrooms, but the organizations have put forward strong arguments. The complaint rests on the question of what defines "direct political activity" which 501c4 organizations must limit to less than 51 percent of their total spending, versus "advocacy," which is not subject to the same limits. The organizations also point out that FEC's general counsel recommended that the case be pursued, only to see it blocked by naked partisanship by Republican commissioners.

Here's one example of what Crossroads GPS calls "advocacy" and what the rest of us think is "direct political activity." The text of one of the ads they ran against Jack Conway in his race in 2010:

“Obamacare” is taking health care in the wrong direction, and Jack Conway has gone the wrong way, too. Conway endorsed “Obamacare,” with its higher taxes and Medicare cuts, and Conway refused to join thirteen other attorneys general and defend Kentucky from Obama’s health care mandate. “Obamacare” and Jack Conway are taking Kentucky’s health care down the wrong road. Tell Jack Conway: turn around, stop defending “Obamacare,” and protect Kentucky from the federal insurance mandate.

Is that ad advocacy, or direct political spending? It does not mention Rand Paul by name, but it suggests that voters register their discontent somehow with Jack Conway, which implies they should vote for his opponent, which is exactly what they did.

Even Stephen Colbert caught on without much effort, as evidenced by his Committee for a Better Tomorrow, Tomorrow ad.

In fact, Colbert submitted a comment on the original FEC complaint, and urged his viewers to do so as well, which they did in force. Sometimes comedy is the best way to make a point.

This is a huge issue. Until now, Citizens United has been viewed as a monolithic cash cow for conservative candidates with absolutely no accountability, even though the Supreme Court ruling explicitly said disclosure was not a violation of the First Amendment.

From the Campaign Legal Center's press release:

“Courts are the only recourse when three Commissioners ignore the laws passed by Congress, ignore the FEC’s own longstanding policies and ignore the call for an investigation by their own General Counsel,” said Paul S. Ryan, Campaign Legal Center Senior Counsel. “As a result of that FEC deadlock the seemingly clear cut violations of the law by Crossroads GPS have continued unabated and other ‘dark money’ groups have been emboldened to follow suit resulting in a massive spike in undisclosed political spending in our elections. We hope that the court sees fit to grant this motion and ensure that every member of the Commission fulfils the duties of their office and enforces the laws passed by Congress.”

Karl Rove may have thought he was home free when his Republican pals deadlocked the panel, but he may have another think coming. One that is far less pleasant for him, and far healthier for our elections process.

For months I have been complaining that our side of things seems to fail to turn to the courts to resolve issues like this, while the right wing uses the courts like a cudgel to smash elections into partisan bits. It is gratifying to see our side use litigation to push forward reasonable disclosure requirements for this dark money.

Watch this space for updates.