This tweet, while in bad taste IMO, was a threat to those who are planning to continue looting and burning buildings in Minneapolis.
I’m not sure if you’ve seen the videos, but there are full scale riots. Rioters completely looted a Target and burned it nearly to the ground.
Is “shooting” the answer to that? Probably not. And hopefully the National Guard is not going to do that.
But at the end of the day, this is the commander in chief making a public statement, and Twitter is editorializing it. Make of that what you will.
Actually no, he doesn't have the capability to threaten institutionalised violence against US CITIZENS which might have or maybe want commit a crime which is not capital and don't even lead to to much jail time.
If he would have the right to do so he would be an authoritarian leader and the US no longer a democracy.
Even if the national guard is dispatched they can just arrest people, not shoot them down (except if that people try to shoot down the national guard, which they don't).