Capital One now says it wants to buy Discover. No actual cash will change hands, according to the proposal, but the all-stock transaction will be worth more than $35 billion. Visa, Mastercard, and American Express are the Bigfoot types in the credit card market. But both Capital One and Discover are important enough that their merger will require a lot of regulatory review, and there is a good deal of suspicion that they will never get the necessary sign-offs. Specifically, the Office of the Comptroller will have to approve. So will the Federal Reserve. Even if they both do, the Justice Department could bring an antitrust action to block the merger. The two parties to the contemplated transaction have begun a PR campaign to persuade us that this merger would actually be GOOD for competition. "The three giants have it all locked up. By uniting, us two outsiders will be able to crash their club force down the rates that cardholders pay!" It is a familia...