Republicans have been highly critical of "Operation Fast and Furious," a federal operation that lost track of firearms purchased by suspected gun smugglers. Some of the weapons have turned up in the wake of shootings in Mexico. Now Democrats are fighting back on behalf of high level Alcohol, Tobacco, Firearms and Explosives officials who claim they didn't know much about the tactics employed by the operation. At a Congressional hearing yesterday, ATF agents said they tried to blow the whistle on the operation. Evan Perez covers the Justice Department for the Wall Street Journal.