The Wisconsin case plays a central role in Robinson’s main obsession—the rise of undisclosed political cash. The 5-4 decision in that case loosened restrictions on ads that do not specifically call for a vote for or against a particular candidate. Today, an armada of non-profit entities known as 501(c)(4) groups, or “social welfare” organizations—which don’t have to disclose their donors—exist to produce these “issue ads,” which factchecking groups find to be the most misleading political ads on the air. In the 2010 cycle, these nonprofits outspent super PACs. (The nonprofit groups also channel funds to the super PACs, which do have to disclose their donors.) This cycle, meanwhile, a July 7 New York Times feature detailed the trend of unreported corporate gifts to nonprofit groups “dedicated to shaping public policy on the state and national levels.” Just a day earlier, Robinson had released his own findings about how 501(c)(4) groups and their “dark money” have been the dominant players in Michigan this spring and summer.

(As one would expect, Robinson is forthcoming about MCFN’s finances. It is supported by the Joyce Foundation of Chicago, which funds quality-of-life initiatives in Great Lakes states. “Beyond that,” Robinson said, “I’ve never gotten an individual contribution more than $2,000.”)

Even the perfect source has limits, of course. Robinson is one guy: as competent and driven as he is, no single person can shoulder all the responsibility for deciphering the shrouded money-and-politics link in Michigan. But while journalists like Graham and Kullgren try to learn from Robinson to do their own digging and double-checking, Robinson can be used as a sort of outsourced reporter, with MCFN’s press releases all but reprinted, as in this post from The Windsor Star, across the river from Detroit in Ontario. In a ten-paragraph story, the Star cites MCFN or Robinson in eight of them. No other source is referenced in the piece.

And while Robinson relies on journalists to get the word out, commercial competition among news outlets can actually limit transparency, he suggested. He often digs up his data on ad spending from the public inspection files at local TV stations. (When I looked at some of those files myself, I frequently saw Robinson’s name on station sign-in logs.) But many of those stations oppose a new FCC rule that will require the files to be posted online, saying it will give rivals easy access to their ad rates.

Robinson said he understands the broadcasters’ resistance—but it is ultimately beside the point. The public “needs to know how much is spent, not how much a spot costs,” he said. “They want a sense of the big picture—what’s spent and who’s spending it. People are frustrated with an ad that will tell them it’s paid for by the ‘Committee for God and Country,’ but won’t really tell you who that is.”

As for how other journalists might carry the beat forward, Robinson suggested a data cooperative that might ease the burden on individual reporters or outlets to dig up their own numbers. MLive, a statewide site that partners with local newspapers, seems to be “fairly well equipped to take it on, because it’s so widely spread out, at least around the Lower Peninsula,” he said. But, “journalists are competitive. It’s hard to say that a journalist in the Grand Rapids market should be in a co-op with a journalist in the Detroit market.”

However it happens, the need for this perfect source to multiply—for more illumination on the flow of money into Michigan, and national, politics—remains pressing. “I can hardly recall a time when a citizen said they didn’t care, they didn’t need to know,” said Robinson. “But legislators are more accountable to funders who don’t want transparency. That’s the officeholder’s dilemma right now: the pull between citizens and anonymous funders. Right now, the funders are winning.”

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Anna Clark is CJR's correspondent for Michigan, Wisconsin, Ohio, and Pennsylvania. A 2011 Fulbright fellow, Clark has written for The Guardian, Grantland, and Salon; blogs at Isak; and can be found on Twitter @annaleighclark. She lives in Detroit.