He doesn't need to invoke. Martial Law.
Civil Law will do just fine.
18 U.S. Code CHAPTER 115—TREASON, SEDITION, AND SUBVERSIVE ACTIVITIES
With this one law he has authority for Federal Law Enforcers to clean up the democrat cities.
It is also Cause for the DOJ to indict half of the House of representatives Democrats, for encouraging idiots to burn loot and destroy.
