Led by Chief Minister Aisha Ramirez, they vow to maintain law and order until the Federation is restored.
When Chairman Clarke sent out the order for martial law, that responsibility fell on the Light Infantry commanders. In those areas not in the direct path of the Caal Invasion, the Light Infantry were responsible for maintaining order. With the abolition of the Federation, these systems feared the rise of an alien dominated empire. The LI planetary commanders came together and formed the "Ministry of Public Safety," with the stated purpose of maintaining the rule of law until the Fed is restored.
Senator Ramirez saw the writing on the wall with the attack on Jennifer's Star. She ran from Avalon back to her home on Phoenix. Once the Caal was defeated, Aisha saw an opportunity, and used her contacts throughout the Light Infantry (she was a former LI officer) to create a new order. After years of being the butt of jokes, the LI are determined not to be second-class to the Fleet and TI anymore. They want a new Federation... with non-magical humans on top for a change.
Behind the Scenes
The "Committee for Public Safety" was the name of the governing body during the French Revolution that executed many of its citizens with the guillotine. Marcus liked using the strange euphemism, which like Homeland Security, has a certain creepiness to it.