John Adams, in a 1775 essay referencing the Roman historian Livy and other sources, wrote that a republic was “a nation of laws, not of men.” As recently as fifty years ago, most Americans would have intuitively understood his point and why it was relevant to their lives. Today, it isn’t clear that the President of the United States, the leaders of the Democratic Party, or the members of our “news” media would grasp the meaning of Adams’ words, much less that they still matter today. We will soon discover if the same can be said of the Supreme Court.

The Court will hear oral arguments this Wednesday in King v. Burwell. The petitioners in this case want the justices to rule that the Obama administration must abide by the provisions of PPACA that govern insurance subsidies. The text of that law, better known as Obamacare, requires that all subsidies must flow through exchanges established by the states. But due to the refusal of 36 states to set up such “marketplaces,” the Obama administration cobbled together federal exchanges in those states through which it is now issuing illegal subsidies.

In other words, the President conducts himself in a manner utterly inconsistent with republican principles and his constitutional oath. Obama obviously believes the law is what he says it is, a delusion evidently shared by his party and the press. He behaves as if he possesses the power to unilaterally change laws and create new ones merely because the opposition party actually opposes his agenda. Adams characterized such behavior as that of “a despot, bound by no law or limitation but his own will; it is a stretch of tyranny beyond absolute monarchy.”

This is, at its core, what King v. Burwell is about. It has nothing do with any “plot to kill health care,” as the New York Times recently put it. Nor does it involve a surreptitious conspiracy to reinvigorate the “states’ rights” movement, as it was described last week in Politico. It isn’t even an attack on Obamacare, though a ruling in favor of David M. King and his fellow plaintiffs would obviously have a profound effect on the future of the “reform” law. It is rather an attempt to prevent the President from doing further violence to the Constitution.

Specifically, it is about the separation of powers doctrine. The Constitution grants the power to tax and spend to Congress alone. Yet the executive branch, under the Obama administration, has brazenly arrogated the power to spend with its IRS rule authorizing the distribution of subsidies through federal exchanges. The original cert petition filed with the Court on behalf of the plaintiffs phrases it as follows: “If the ACA means what it says… the IRS is illegally spending billions of taxpayer dollars every month without congressional authority.”

Moreover, the illegal decision to distribute subsidies via federal exchanges implicitly usurps Congress’s taxing power as well. These subsidies activate the employer mandate and the financial penalties associated with noncompliance. As legal scholars Michael Cannon and Jonathan Adler testified before the House Committee on Oversight and Reform shortly after the IRS rule was promulgated, “It thus triggers a $2,000-per-employee tax on employers and appropriates billions of dollars to private health insurance companies in states with a federal Exchange.”

If the Court permits this usurpation of such crucial congressional prerogatives, the result would be a quantum leap forward in presidential power. This is precisely what the separation of powers was devised to prevent. Yet, as perilous as it would be to permit the executive branch to accumulate more power than it has already acquired since 2009, that is what SCOTUS is being pressured to do. Since the Court agreed to hear King, there has been a concerted campaign by left-leaning legal scholars, politicians, and pundits to push its deliberations in that direction.

Much of this pressure on the Court has been focused on Chief Justice John Roberts, which is to be expected considering his craven ruling in NFIB v. Sebelius. Brianne J. Gorod, of the Constitutional Accountability Center, provides this all-too-typical example in the Los Angeles Times, “When the Supreme Court hears oral arguments in King vs. Burwell next week, all eyes will be on Chief Justice John G. Roberts.… There’s one very good reason to think the chief justice will rule for the government again: He’s too good a lawyer to do otherwise.”

Gorod’s point is as subtle as a drone strike. She might just as well have written, “Nice reputation you got there, Johnny. Hate to see anything happen to it.” And, if you doubt that Roberts can be swayed by such tactics, remember that a very similar intimidation campaign preceded his bizarre 2012 ruling on the individual mandate. William Jacobson of Cornell Law School puts it thus: “This pressure reportedly caused Roberts to change his vote, and to join with the four liberal members of the Court in finding the mandate justified under Congress’ taxing power.”

If Roberts is once again cowed, and allows the IRS to rewrite an act of Congress to suit the Obama administration’s political agenda, our President will regard it as a sign that he has safely crossed the constitutional Rubicon. It’s no coincidence that John Adams included Livy among those who influenced his view that a republic was “a nation of laws, not of men.” Livy personally witnessed the events that converted Rome from the former to the latter. If the Court caves again, we will have witnessed the same fundamental transformation of our country.