> There are laws that created departments that the president does not have the power to destroy.

That's true but what you're leaving out is that those laws were passed by Congress to give their authority away to these agencies and give the management of them away to the executive branch.

Congress is wholly at fault for all of the power they've ceded to the executive.

Trump has the authority, granted by Congress, to appoint the people in charge of those agencies and has the authority to dictate their agenda (by appointing someone who will carry it out).

> One study estimates that the Supreme Court will be "conservative"

First of all, "one study..." isn't a great way to make a point but, regardless, "conservative" justices doesn't mean politically conservative, it means judicially conservative and that is a completely separate concept.

Trump has been ruled against several times already on judicially conservative grounds.