(I found this as I was browsing through some of the Katrina info that has been posted - worth repeating...):
"FEMA's enormous powers can be triggered easily. In any form of domestic or foreign problem, perceived and not always actual, emergency powers can be enacted. The President of the United States now has broader powers to declare martial law, which activates FEMA's extraordinary powers. Martial law can be declared during time of increased tension overseas, economic problems within the United States, such as a depression, civil unrest, such as demonstrations or scenes like the Los Angeles riots, and in a drug crisis. These Presidential powers have increased with successive Crime Bills, particularly the 1991 and 1993 Crime Bills, which increase the power to suspend the rights guaranteed under the Constitution and to seize property of those suspected of being drug dealers, to individuals who participate in a public protest or demonstration. Under emergency plans already in existence, the power exists to suspend the Constitution and turn over the reigns of government to FEMA and appointing military commanders to run state and local governments. FEMA then would have the right to order the detention of anyone whom there is reasonable ground to believe...will engage in, or probably conspire with others to engage in acts of espionage or sabotage. The plan also authorized the establishment of concentration camps for detaining the accused, but no trial.
Three times since 1984, FEMA stood on the threshold of taking control of the nation. Once under President Reagan in 1984, and twice under President Bush in 1990 and 1992. But under those three scenarios, there was not a sufficient crisis to warrant risking martial law. Most experts on the subject of FEMA and Martial Law insisted that a crisis has to appear dangerous enough for the people of the United States before they would tolerate or accept complete government takeover. The typical crisis needed would be threat of imminent nuclear war, rioting in several U.S. cites simultaneously, a series of national disasters that affect widespread danger to the populous, massive terrorist attacks, a depression in which tens of millions are unemployed and without financial resources, or a major environmental disaster.
THREE TIMES FEMA STOOD BY READY FOR EMERGENCY
In April 1984, President Reagan signed Presidential Director Number 54 that allowed FEMA to engage in a secret national "readiness exercise" under the code name of REX 84. The exercise was to test FEMA's readiness to assume military authority in the event of a "State of Domestic National Emergency" concurrent with the launching of a direct United States military operation in Central America. The plan called for the deputation of U.S. military and National Guard units so that they could legally be used for domestic law enforcement. These units would be assigned to conduct sweeps and take into custody an estimated 400,000 undocumented Central American immigrants in the United States. The immigrants would be interned at 10 detention centers to be set up at military bases throughout the country.
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On July 5, 1987, the Miami Herald published reports on FEMA's new goals. The goal was to suspend the Constitution in the event of a national crisis, such as nuclear war, violent and widespread internal dissent, or national opposition to a U.S. military invasion abroad. Lt. Col. North was the architect. National Security Directive Number 52 issued in August 1982, pertains to the "Use of National Guard Troops to Quell Disturbances."
The crux of the problem is that FEMA has the power to turn the United States into a police state in time of a real crisis or a manufactured crisis. Lt. Col. North virtually established the apparatus for dictatorship. Only the criticism of the Attorney General prevented the plans from being adopted. But intelligence reports indicate that FEMA has a folder with 22 Executive Orders for the President to sign in case of an emergency. It is believed those Executive Orders contain the framework of North's concepts, delayed by criticism but never truly abandoned."
http://www.sonic.net/sentinel/gvcon6.html