The mechanism: The Credit Card Competition Act — reintroduced by Sens. Durbin and Marshall in January 2026 and endorsed by President Trump — would force banks with over $100 billion in assets to enable at least two unaffiliated networks on their credit cards, and bar penalizing merchants who route away from Visa or Mastercard. Modeled on the Durbin Amendment's debit-routing mandate, it takes aim at the exclusivity deals that let Visa and Mastercard set both the rails and the price. Critically, the bill exempts 3-party closed-loop networks — where the issuer is the network — meaning American Express and Discover are carved out entirely. This is not a symmetric hit. It's a structural one, and it lands hardest on whichever network has the most exclusivity-locked, high-take-rate volume to lose.
Who cashes in: