What are Title 10, the Insurrection Act and the Posse Comitatus Act, and When Can the President Use Them?  Spoiler: LA Doesn’t Likely Qualify.

In a highly controversial action, President Trump is testing the reach of his powers by sending 4700 military personnel into Los Angeles to suppress protests. What are Title 10, the Insurrection Act and the Posse Comitatus Act?