The retailers are stepping up their defense of the Durbin Amendment and the interchange cap.
Majority whip, in speech Thursday, said credit union and small banks are "becoming part of big banking."
Illinois senator asks ABA to back off from "massive lobbying effort."
TCF National Bank, a major issuer of debit cards, has gone to a higher court to try again on blocking new cap.
The Illinois Democrat tells CEO "you and your bank already are making money hand over fist."
Efforts to delay the implementation of the Federal Reserve’s debit interchange rule continued on Capitol Hill and at the grassroots level last week.