The Senate continued its surprise populist turn on financial reform Friday, voting for limits on fees charged to stores by banks on credit- and debit-card transactions. The move was a hard-fought victory for retailers, who have asked Congress to take action on the fees for years. In total, 64 senators voted for the measure, including 17 Republicans. The change could save billions of dollars for businesses that make heavy use of customer credit- and debit-card payments, from small restaurants to retail giants like Walmart, potentially lowering costs for consumers as well. Defenders of banks warn that the reduced profits could be felt by customers in the form of less favorable reward programs on cards.