What if the President decided that he wanted to take an extended golf vacation for a couple of years, broken only by the mandated State of the Union address? That would not be illegal, but would certainly be an issue of misdemeanor.
You're right, negligence can be impeachable. But an impeachment still has to involve some kind of action (or inaction) that's harmful, and it would need to be proved. If he's conducting these activities behind the scenes, how is anyone in Congress to know if he's abusing his power? It's still an unrealistic check.
A bit wrong here. A State of the Union address was never mandated by the Constitution. A written form (which could be made in the form of a speech) was mentioned in the Constitution...
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