>Either the president does not know the constitutional limits on his power, or he knows them but still thinks it's a good idea to claim power that he does not have. I'm not sure which is worse.

Or he knows what he is allowed to do and is just saying stupid crap like he usually does. Trump doesn't have a filter and just says/tweets whatever pops into his head. This could be another example of that.

Trump loves twitter. If he actually had a problem with it, he could just stop posting.

So I think it's more of a third choice - He doesn't care if he has the power, he's just creating chaos and conflict to excite his base, as he has been doing for years.