We are finding out in real time that the president can actually do a lot of things, simply because nobody is stopping him.
I'm not saying that that could never happen, but a) it sure sounds like an uphill battle and b) it's not the same thing as the president (one person) doing whatever they feel like regardless of the law.
We have somehow made it a habit to ignore the inconvenient parts of the constitution when they create problems, rather than going through the enumerated process to amend them. Yes, it’s hard to amend the constitution, but that’s the point!