No. He should order it. But not personally, that's the job of the attorney general. The area is under marshall law now, as of yesterday I think, so the Gov. and mayor are about as important as Jesse Jackson now. They're out by default of having lost control.
Do you understand the Constitution and States rights? He can't do anything he isn't invited to do.
You have a link for martial law being declared?
No, the Governor of the state initiates the marshal law plan that was legislatedby the Louisiana government. this is not covered in the Constitution of the United States. This is one of those things left to the states to legislate...which part of the Constitution guarrantees that right to the states?