Obama will claim we need a national police force in order to fight terrorism and crime. The Boston bombing is a useful start, especially when combined with random shootings by crazy people.
Where will he get his "national police"? The NaPo will be recruited from "young out-of-work urban men" and it will be hailed as a cure for the economic malaise of the inner cities.
In other words, Obama will put a thin veneer of training and military structure on urban gangs, and send them out to channel their violence against Obama's enemies.