The GP is using a snowclone of the original: "It couldn't have happened to a nicer guy".
For example, if your boss is very rude and disparaging, but then he gets fired, you would say, sarcastically, "It couldn't have happened to a nicer guy", implying there's some element of karma at work.
By analogy, GP is saying these tarrifs were an undeserving act of vengeance. I assume "undeserved" in the sense that it wasn't deserved by those on the receiving end.
Roger. Surely it's twisted a bit more with the kind of things Trump spews, but for instance a great leader wins a well-deserved Nobel Prize, and you say it couldn't have happened to a more deserving contender.
You say the same thing when a complete moron fails to win the same prize.
For example, if your boss is very rude and disparaging, but then he gets fired, you would say, sarcastically, "It couldn't have happened to a nicer guy", implying there's some element of karma at work.
By analogy, GP is saying these tarrifs were an undeserving act of vengeance. I assume "undeserved" in the sense that it wasn't deserved by those on the receiving end.