WASHINGTON — The Senate Banking Committee has rejected President Bush's nomination of Robert Clarke to serve a second five-year term as comptroller of the currency.His opponents, all 12 Democratic members of the committee, charged Wednesday Mr. Clarke was responsible for the nation's bank failures because his office was too lax in its regulation. But his supporters, all nine Republicans, charged that he was being made a scapegoat. One Republican, Sen. Pete Domenici of New Mexico, suggested that the panel's chairman, Sen. Don Riegle Jr. (D) of Michigan, was aiming to make Clarke a scapegoat for the bank failures in an attempt to cover up his own involvement in the savings and loan scandal. Senator Riegle has been accused of pressuring thrift regulators not to shut down Lincoln Savings and Loan, a California thrift, after he received campaign contributions from Lincoln's chief, Charles Keating. Other Republicans acknowledged that Clarke had made mistakes in regulating banks, but said Congress made the biggest mistake of all when it refused several years ago to authorize sufficient money for regulators to close down failing thrifts. That delayed the thrift closures, costing taxpayers billions of dollars. Noting that a government study indicated banks regulated by Clarke had more failures than other banks, Sen. Richard Shelby (D) of Alabama said, "I have to believe we can do better." Clarke's renomination battle had taken on larger political dimensions, as the nation's faltering economy and an anticipated $70 billion government loan to handle failing banks are expected to become issues in the upcoming presidential campaign.