Melissa Merz, a former press secretary for Durbin, lobbied for Walmart on the financial regulation bill, as did former Durbin legislative aide Donni Turner. The Durbin alumna were both at the Podesta Group, and the firm’s lobbying filings indicate both lobbied on “Senate financial services regulatory reform legislation.”

At the same time, these retail lobbyists were helping fund Durbin’s campaign. Daily Caller reporter Jonathan Strong wrote “one month after the Dodd-Frank financial reform bill passed, both of those former aides, Melissa Merz and Donni Turner, attended an Aug. 10 fundraiser for Durbin hosted by the Podesta Group. A group of lobbyists mostly from the Podesta Group gave Durbin $5,000 on Aug. 10 and a $5,000 check from Walmart’s PAC cleared shortly afterward, on Aug. 27.”

The returns to the retail industry were huge. As the Federal Reserve prepared its rules setting the maximum per-purchase interchange fee, a Home Depot executive told investors on a conference call “Based on the Fed’s draft regulations, we think the benefit to the Home Depot could be $35 million a year.”

That $35 million Home Depot gain is a $35 million loss for banks and credit-card processors. Their interchange revenue was central to the business model that allowed banks to offer free checking and free debit-card use.

That business model is now illegal, and so Bank of America has switched to the model they find second best. If they can’t make the stores cover the costs of debit cards, make the consumers pay a share. The American Bankers Association calls Bank of America’s $5-a-month charge “the Durbin fee.”