Behind the scenes, a power struggle emerged, as federal officials tried to wrest authority from Louisiana Gov. Kathleen Babineaux Blanco (D). Shortly before midnight Friday, the Bush administration sent her a proposed legal memorandum asking her to request a federal takeover of the evacuation of New Orleans, a source within the state's emergency operations center said Saturday. The administration sought unified control over all local police and state National Guard units reporting to the governor. Louisiana officials rejected the request after talks throughout the night, concerned that such a move would be comparable to a federal declaration of martial law....