There's no doubt that the riots happened because local police were ordered to stand down. Nor is there any doubt that police are being scapegoated for ongoing situations which progressive politicos have utterly failed to fix.
But Trump's legal authority to dispatch armed Federal agents against the rioters is on the shady side of murky at best.
Federalism and Law and Order
“The administration's particular actions are dubious under federal statutes, and they are misguided from the perspective of deescalating violence.”
The Department of Homeland Security is an abomination that never should have existed. It's agents aren't trained in crowd control and apparently have no idea how to do much more than thump heads.
I agree that there should be a law and order solution. I disagree that the President and the Federal government have the authority, mandate, or obligation to provide that solution beyond the military.
This is how it ALWAYS starts. Without fail. Time and time again. Expand government power and authority "for the emergency" and it WILL be used against you. Probably sooner than you think.
Remember this when the next Democrat President uses DHS in questionable ways and you start wondering how we gave a government agency that power.
It's not a matter of the FedGovs using force, it's that there is no Constitutional provision for using armed Federal agents. There is no provision for Federal agents. Armed forces, yes, militia, yes. There is no provision in the Constitution for law enforcement officers, much less armed ones.
The Federal government has no powers to arm agents. It can arm the military and send it in.
Ordering military intervention in domestic affairs is a special circumstance. It's outside the ordinary and people will be watching and questioning closely. Most importantly, it's temporary. Afterwards, there is no agency that can be casually ordered into action. There's no mechanism for government agents to persecute citizens. But creating or empowering an agency means it's there from then on out. The power exists just waiting for a reason. Do you think when Bush League signed the Patriot Act he had any idea how it would be misused? Not just by his successor, but by he himself? The American government has a long history of breaking it's promises
Let Trump send in troops if absolutely necessary and as his predecessors did. But armed Federal agents are illegal and unconstitutional. I don't really approve, but at least using the military is Constitutional.
There is precedent yes, but the Federal government does not possess legal authority for armed agents. The Founders had some very strong reasons for not wanting the Federal government to arm anyone except the military.
Having read the Federalist papers, the Anti-Federalist papers, and some of the debate of the Constitutional convention, it amazes me what did and didn't make it into the document. Of course the classic example is the three-fifths compromise, but that is hardly the only thing.
One of the more interesting is if the new document needed a bill of rights. Many of the delegates felt that specifically enumerating rights would mean that any right not listed would not be recognized by the new national government. That is why the powers of government were very carefully and explicitly stated. And that is why Congress proposed twelve amendments in 1789.
Classic liberals have raised questions about armed Federal agents since before the Civil War. I've not read anything about it prior to that. After the Civil War, America's first gun control laws were introduced to keep guns out the hands of freed slaves. That was probably what started the discussion.
The Civil Rights Act of 1871 and the Ku Klux Klan Act of 1871 laid the ground work for "qualified immunity" for police and government agents. After WWI, new gun laws meant certain weapons could only be used by the military or designated government agents.
But the real consideration goes back to why there is a Second Amendment in the first place. It's not to protect hunters, it's so citizens could defend themselves and their neighbors against government tyranny.
We've lost the lessons of the Whiskey Rebellion.