Many of the protesters do not live in Ferguson. Many of the people of Ferguson are tired of the protests and destruction and would like to go back to making a living, being able to drive to and from the store, and getting some sleep.
The police have a sworn obligation to uphold the law and maintain order. If the local police cannot fulfill that mandate, the county, state, or federal government will. I for one prefer local law enforcement over anything provided by the US Department of Justice.
The weatherman will soon bring an end to the protest season in Ferguson. The people I've seen in most of the Ferguson protests do not look like the hardy, hold hands and sing KumByYah in a freezing rain or snow type.
Be safe.