However, Mitt Romney, the leading Republican in the race who has raised $62.7 million (a little less than half as much as Obama), lists only 16 people as bundlers -- less than 4 percent the size of Obama's team -- bringing in $2.4 million. The difference? Romney is following the letter of the law -- the law that says candidates need only disclose the names of bundlers who are also registered federal lobbyists. (For the record, Obama's campaign does not accept money from federally registered lobbyists, but it has accepted money from people who oversee lobbying for consulting shops or private companies). In the same spirit, Rick Santorum's campaign has listed no bundlers, and neither has Gingrich's. Ron Paul has said he does not use bundlers.

Using bundlers to help bring in the tremendous amounts of cash needed for a presidential campaign has been used to great effect in recent races. Bundlers, who are often corporate leaders, lobbyists or Wall Street executives, can funnel hundreds of thousands of dollars, potentially even millions, to a campaign, despite the fact that individually they can give only $2,500 to a candidate for the primary season and the same for the general election.

George W. Bush set a precedent of disclosing the ones who raised at least $100,000 -- he called them "Pioneers" -- during his 2000 campaign. The subsequent Republican and Democratic party nominees, including Obama in 2008, disclosed their major bundlers as well.

That's one reason why the Center for Responsive Politics and eight other government watchdog organizations this week are asking the Republican candidates to divulge the names of ALL the bundlers for their campaigns and any joint fundraising committees that benefit them. We’re also asking them and Obama to list the specific amount that each bundler has raised, rather than simply a range, as Obama currently provides. And we’re also calling for the candidates to provide the city, state, zip code, occupation and employer of each bundler – information the Federal Election Commission requires of all donors. 

More important than precedent, disclosing information about these critically important people on which campaigns depend so heavily is the right thing to do. We all know modern campaigns raise and spend millions, so candidates shouldn't pretend bundlers don't exist. Bring them out into the open and tell us who they are. Yes, candidates will be judged by the company they keep and those they select to represent and advise them - as they should be. But they have more to fear -- and will create more doubt and suspicion among the public -- by operating in the dark.  

Krumholz is the executive director of the non-partisan, nonprofit Center for Responsive Politics in Washington DC, which tracks money in politics and operates the website