They would scream “tyranny” even if he pats a kitten. We know that.
He talkeda about the Insurrection Act with Judge Jeanine about 3 or so weeks ago, said he wasn’t going to invoke it for 250 antifas. Good interview, I can get link if you want, it’s on Judge Jeanine’s twitter, parts 1 and 2.
But if, or imho, when, the violence gets worse and more widespread, he’ll clearly have every legitimate and constitutional authority to invoke it. And then the real FUN begins.
The governor supposedly has to call for POTUS to help; the mayor could petition the governor to act, which looks like what happened in Louisville. IMO, if the governor(s) and mayors would rather let the cities burn so that they can blame POTUS, local citizens could band together and petition the Prez to restore law and order.
For POTUS to act with no state or local call - while incomprehensible - can lead to trouble. POTUS could declare an insurrection and name state and local officials complicit in order to act - sort of what Lincoln had to do with no local cooperation - but that led to the War Between the States. The Pacific coastal states have already threatened to secede from the Union - which we cannot allow to happen.
If POTUS wants to act unilaterally, I support him!