Actually, the President can nationalize any states National Guard at any time and the governor can't do a damned thing about it. I think it was Eisenhower who did it to George Wallace and Kennedy did it in Arkansas, in both cases to enforce court ordered ending of official segregation. The problem is that as a nationalized force they fall under Posse Comitatus and can't be involved in law enforcement, only keeping the piece. They lose the power to arrest, for example.
Bush wanted to put the National Guard under the command of the Homeland Security folks to clean up control and logistics issues, but not nationalize them so that they would still be technically able to act in a law enforcement role. That's what Blanco refused to allow.
I've submitted a proposal to the offices of Frist, Alexander and Blackburn, along with the commanding officer of the Coast Guard, of expanding the Coast Guard to include responsibility for our borders not just our sea boundaries. I've suggested that we pattern 3 to 6 units based on the TO&E of a Marine Expeditionary Unit, adapting their equipment to a SAR and border enforcement role. Station them strategically along the southern border, say places like North and East of Mexicali, South of Tucson, in the vicinity of El Paso, across the Rio Grande from Lajitas, the Laredo area and near Brownsville. They could operate along the border in conjunction with the border patrol, which would probably be folded into their command and control structure. They would also perform the traditional SAR and counter smuggling tasks that are part of the culture of the Coast Guard. In addition they'd be available as a rapid reaction force for natural or man made disasters anywhere in the country. I'd staff them with Marines who were looking to move on but not yet ready to get out of uniform. You could also make it possible to chop them to the Marines or Marine units to them as needed.
So far no one's gotten back to me, though a few friends in the Marine Reserves I've talked to about it seemed intrigued.
Didn't X42 break the law when he had Weasley Clark send in the tanks and flame throwers at WACO?