That and you can never underestimate how people react when they’re literally starving to death. Through a multitude of reasons (like low blood sugar which increases stress hormones and just basic survival instinct) humans become extremely desperate and hostile when they go long enough without something to eat.

I'd think something like martial law would only need maybe 30 to 40% of domestic support. That is, if it's an actual coordinated military with specific goals and not what would probably exist which is wild brutish flailing and random acts of terror against marginalized people. That second thing is basically what we have now and I can't imagine the Trump admin would suddenly and magically have its shit together during bouts of national riots.