One more question: Is it even legal for the regular U.S. military to assume operations within the USA, even for disaster relief?
Weren't regular troops (ie. not National Guard) brought into the South during the integration battles in the 1950s?
Yes but not in a law enforcement role. That is restricted to the State National Guard under command of the Gov. There are certain things the Gov has to do. I think declare a state of emergency or something before she can send in the Guard. It looks like President Bush FINALLY got the State of Lousiana to accept Federal Troops on Friday when he was there. They can be used at the invitation of the State Gov. The other case is if the State or Local authority is in defiance of Federal Authority. That is why Esinhower could send the troops into Little Rock in 1956. However, the State is STILL refusing to relase authority for operations to the Feds. Looks like Gov Blanco is STILL in CYA mode.