Governor Blanco must make a formal request for federal military assistance. There are particular words of art she must use. I think a proclamation of martial law in the affected areas is part of it, but am not sure about that. But federal assistance is limited absent the particular words of art by Governor Blanco. Also see post No. 406.
whats the downside to declaring martial law? I can't understand why it isn't done. How bad does it have to get?