The Founders’ vision of constitutional government could prove the ultimate winner in the dispute between President Trump and a fired board member of a federal agency that’s purportedly independent. The case, argued before the Supreme Court this morning, is captioned Trump v. Slaughter. Yet the loser in the controversy could be the Deep State that has emerged as an unelected and unaccountable branch of government.

Rarely do arguments before the Supreme Court drill as close to the constitutional bedrock as they do in the dispute over Mr. Trump’s firing of a member of the board of the Federal Trade Commission, Rebecca Slaughter. Mr. Trump’s solicitor general, John Sauer, urged the justices to allow Mr. Trump’s termination of Ms. Slaughter without cause. The idea is to restore the Constitution’s balance of separated powers. 

The “court’s duty,” General Sauer said, is “to ensure that the executive branch is overseen by a President accountable to the people.” To achieve that goal would mean reversing a 90-year-old precedent. In 1935, the Nine ruled in Humphrey’s Executor v. United States that FDR couldn’t fire an FTC board member. That ruling, per General Sauer, “poses a direct threat to our constitutional structure” and “the liberty of the American people.”

The argument put forward by General Sauer reflects the logic of what’s known in legal shorthand as the unitary executive theory. This vision of the Constitution grasps that the Framers granted solely to the president all the executive powers of the federal government. So it does not compute, constitutionally, for Congress, as it did with the FTC, to create a supposedly independent and nonpartisan executive agency.

The same illogic led Congress to transfer the federal government’s monetary powers to the Federal Reserve. Mr. Trump may not now — or yet — be contesting the avowed independence of the central bank. Even so, General Sauer averred that Congress “lacks authority” to “create these headless agencies” that “have no boss and are not answerable to the voters.” Hence Mr. Trump’s restoration of presidential prerogatives by taking control of the FTC.

Striking the New Deal-era Humphrey’s Executor precedent would weaken the legal underpinnings of the Deep State. That’s the term to describe the bureaucracy that bloomed under FDR and metastasized under later presidencies, Democratic and Republican. Yet reversing that expansion of power by the administrative state is unlikely to be achieved by one high court ruling. Justice Neil Gorsuch hinted at this in a colloquy with General Sauer. 

Congress had intended agencies like the FTC would use legislative-like powers under the aegis of the executive. Justice Gorsuch mused on whether this delegation should be ended. For years, he suggested, the high court has “taken a hands-off approach to that problem” via what’s known to legal sages as the “intelligible principle” doctrine. Meaning Congress could delegate away core powers provided boundaries were set on the delegated authority.

Justice Gorsuch lamented that the doctrine “has grown increasingly toothless with time.” Congress’s abdication — and the Nine’s — enabled the Deep State. If “independent agencies” are “now going to be controlled by the President,” he mooted, it seems “imperative to do something about it.” That means reviving “the intelligible principle doctrine” to “recognize that Congress cannot delegate its legislative authority.” Asked he: “Is the water warm, General?”