While I understand that many people do not like Trump and that his tweet isn't what would be expected from a president I'm not sure what they want Trump to do about it. The president's powers to interfere at the state and local level is quite limited. The author doesn't seem familiar with Posse Comitatus.

https://en.m.wikipedia.org/wiki/Posse_Comitatus_Act

The inflammatory tweet, when you read it without the emotional component, Trump is doing what he's allowed to do. He's offering the military if requested by the governor. That is really the key thing. As long as the state government is in place and functional the governor is in control.