During the 2012 elections—and ever since—coverage of campaign finance has focused heavily on the role of “dark money”: the unlimited donations directed to nonprofit groups and trade associations that are not required to disclose their donors.

Countless reports by journalists and transparency advocates have sought to trace the origins of dark money donations. Almost as frequent are the efforts to convince, cajole, or shame government entities—from Congress to the Federal Elections Commission to the Internal Revenue Service—to adopt new rules requiring that these donations be disclosed in the future.

But so far, a creative new method that dark money opponents have seized on to drag secret donations—at least, the ones that come from public companies—into the open has attracted relatively little attention. As Nicholas Confessore reported last week in The New York Times, these advocates are arguing that the cause of disclosure should be taken up by an agency that has traditionally stayed away from regulating political contributions: the Securities and Exchange Commission (SEC). And, according to the Times report, they have a real chance of success.

The SEC is now weighing whether to propose a rule that would require publicly traded companies to disclose their political donations to their shareholders. The move would effectively end the secrecy that surrounds such contributions when they are made to dark money organizations.

The campaign for SEC action is at a crossroads: the SEC indicated that it would decide whether to propose such a rule in April, a deadline it has just missed. On Tuesday, a coalition of leading good government groups sent a scathing letter to President Obama, blasting him for “the absence of your leadership on campaign finance issues” and urging support for the SEC rule as one way to redeem himself.

As the SEC considers whether to act, journalists—especially state and local political reporters who rarely delve into dark money and don’t get to cover money-in-politics full-time—face an important challenge. Such a rule could upend the campaign finance system not only at the national but also at the state and local levels, and the details and context are important. The Q & A explainer below provides background to help reporters get coverage of the SEC proposal right.

Hold on. The Securities and Exchange Commission is thinking of doing what?

The SEC got a petition in 2011 from 10 noted law professors who urged the commission to “require public companies to disclose to shareholders the use of corporate resources for political activities.” The rule would require reports to shareholders at regular intervals detailing any spending on politics.

In recent months, a group of Democratic officials, shareholder activists, and pension funds have mounted a forceful campaign support of the petition, helping to generate nearly half a million comments. In January, the SEC indicated it would decide whether to propose such a rule by April.

Can they do that? Does the Security and Exchange Commission have the authority to regulate political spending?

The SEC’s mandate is to protect investors and maintain fair and orderly markets. According to the law professors’ petition, corporate political spending is not only of interest to investors but “necessary for corporate accountability and oversight mechanisms to work.” The petitioners note that the quantity and significance of this spending has increased substantially since the Citizens United decision opened the door to unlimited contributions to political groups.

Opponents of the petition argue that the proposal falls outside the SEC’s purview. Blair Holmes, a spokeswoman for the Chamber of Commerce, told The New York Times that “the funds expended by publicly traded companies for political and trade association engagement are immaterial to the company’s bottom line.” Opponents say the proposal’s real objective is to chill political spending by corporations by exposing them to public intimidation—an outcome that could decrease their value to shareholders.

It seems like this debate could be avoided if the issue were addressed by a government agency that were a more natural fit, like the Federal Election Commission or Internal Revenue Service. Why isn’t this being handled by anyone else?

In some ways, the SEC is a last resort. Reform groups have pressed the FEC to take enforcement actions against violators of campaign finance laws, but it has been paralyzed by partisan gridlock and five of its six commissioners are serving as lame ducks whose terms have already expired. Reformers also have urged the IRS to revoke the tax status of nonprofit groups that misrepresent their plans to spend on politics, with equally little success. The angry letter to President Obama by good government groups on Tuesday forcefully articulated these frustrations.

Political nonprofits in particular have made it possible for special interests to spend on politics with an expectation of secrecy. The proposed SEC rule would shut down an avenue for undisclosed political spending that no other agency has indicated it will address, even when the spending appears to violate other rules by these agencies.

Who is in charge of making the decision?

The SEC must decide independently whether to propose the rule. Currently, five of the commission’s six seats are filled, with three Democratic appointees and two Republican appointees. The swing vote, according to the Times, is likely to be the newly confirmed chairwoman, Mary Jo White.

She is expected to weigh not only the merits of the rule but also how to use her agency’s limited resources and political capital. The SEC is already locked in a lengthy struggle to implement the Dodd-Frank financial reform bill, and proposing a new restriction on corporate political spending would likely result in another pitched battle with Wall Street and other powerful business interests.

The SEC cited these challenges in a statement to CJR that suggested it may further delay its decision. “The staff is considering whether to make a recommendation, but the timing of any recommendation will be influenced by the ongoing workload of Dodd-Frank and JOBS Act rulemaking,” said SEC spokesman John Nester.

That seems like a tough call for the SEC. Can anyone influence its decision?

Both sides are definitely trying. As we noted, the petition for the rule gained momentum due to the efforts of a Democratic-leaning coalition to raise a groundswell of support for it. Not coincidentally, the corporations, trade associations, and political nonprofits that would be affected by the rule predominantly support Republicans.

Groups such as the Chamber of Commerce, Construction Industry Round Table, and National Association of Manufacturers have lobbied hard to keep the SEC from acting, according to the Sunlight Foundation. Congressional Republicans have also gotten involved. In April, Rep. Scott Garrett (R- New Jersey), who chairs the House subcommittee that oversees the SEC, introduced legislation that would ban the agency from issuing political disclosure regulations.

Would the rule really make a difference? How much of an effect would it have on dark money in politics?

As the growing campaigns on each side of the rule suggest, it does have the potential to make a big difference. Trade associations and political nonprofits have become hugely popular targets for donations precisely because they are not required to disclose their donors—an attribute that is highly appealing to powerful companies that want to influence politics but don’t want alienate large numbers of consumers (or politicians of the opposing party). If the SEC were to impose the rule, it would drag a class of dark money donors in the sunlight.

If the SEC does adopt the rule, one crucial question would be whether donations to political nonprofits and trade associations, currently the main conduits for dark money, would in fact be covered. Direct donations to candidates, which would also be included under the rule, must already be disclosed to the Federal Election Commission. The law professors’ petition urged the SEC to develop criteria specifying what categories of recipient groups should be included, but pointedly noted that disclosure of “corporate contributions to intermediaries that spend a large fraction of their funds on politics” is warranted.

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Sasha Chavkin covers political money and influence for CJR's United States Project, our politics and policy desk. He has written for ProPublica, the Center for Public Integrity, and The New York World. Follow him on Twitter @sashachavkin.