I think you are right; a case could be made for criminally prosecuting Krugman. I hope this is done and even if the govt loses; hopefully, it will cost Krugman so much money, every journalist will think twice before they lie. Also, I wonder if this tweet could be considered an act of terrorism?
I think it was lofted to embellish the charge that Trump has somehow been negligent with regard to Puerto Rico.
I’m sure it is intended to move public opinion, but here it wouldn’t be out of direct fear, as much as simply wanting to get rid of Trump.
That seems political to me, even if I hate it. I do think it is a lie, and could be attacked for that with the intent to misinform the public and undermine the government.
Some might see it as an act of terrorism. It might also be seen as conspiring to harm the federal government.
You have to draft these things carefully, so simply disagreements don’t become a reason for the Left to charge folks with crimes for more normal things.