[davetufts]

One option relies on the rule of law; the other relies on the ad-hoc whim of whoever is in charge. While the result would be the same, there is a huge difference.

Nowhere in the law does Congress even have the authority to extend Mueller's stay for two years. If we're OK with that, we're essentially OK with Congress granting themselves powers outside the law. Congress certainly has the power to pass a new law removing or extending tenure. They do not have the authority to extend Mueller's tenure.

[AaronI]

They can pass an act designated as "private law" (aka slip laws), which can apply to specific individuals and afford relief from another law or grant benefits/powers that are not available under the general law. So Congress actually does have the authority to extend his tenure.

[davetufts]

Your example requires that Congress pass legislation, which is exactly what I'm making a case for. In practice, and after reading this article, I doubt that will be the way it goes down.