In today's decision in Trump v. Slaughter, the Supreme Court ruled that laws protecting the heads of "independent" executive agencies from firing are unconstitutional, because they infringe on the president's constitutional removal authority. In my last post, I noted that the exact scope of this principle is unclear, given the exception the Court carved out for members of the Federal Reserve Board in Trump v. Cook, also issued today. But let's assume that, after Slaughter, protection against removal really is unconstitutional for the heads of all or nearly all previously "independent" federal agencies. If so, I would suggest that that renders the very existence of at least some of these agencies subject to legal challenge on the grounds that the removal protection provisions are not "severable" from the rest.
In his concurring opinion in Slaughter, Justice Neil Gorsuch rightly highlights that Congress might not have created many of the independent agencies in the first place (or at least not given them as much power) if they had known their leadership would be subject to the complete control of the president:
