WASHINGTON — The constitutional showdown that followed the FBI's search of a congressman's office came down to this: The House threatened budgetary retaliation against the Justice Department. Justice officials raised the prospect of resigning. That scenario, as described Saturday by a senior administration official, set the stage for President Bush's intervention into the fight over the FBI's search of the office of Rep. William Jefferson, D-La., an eight-term lawmaker being investigated on bribery allegations. During contentious conversations between the Department of Justice and the House, top law enforcement officials indicated that they'd rather quit than return documents FBI agents, armed...