Editor’s Note: Joseph J. Ellis is an American historian who won the Pulitzer Prize for “Founding Brothers.” He is the author of “American Dialogue: The Founding Fathers and Us.” The views expressed here are the author’s. View more opinion on CNN.

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Before there was Donald Trump, there were Bill Clinton, Richard Nixon and Andrew Johnson, all presidents who were impeached or, in Nixon’s case, resigned before the impeachment vote could occur. There are compelling legal reasons to regard this list as complete. Let me suggest there are also compelling historical reasons to add George III to the list.

Joseph J. Ellis

For legal scholars, the seminal document of the American founding is the Constitution. That makes splendid sense, especially when it comes to assessing any putative violation of executive power, since the Constitution defines such power in Article II. It also provides the language for impeaching and removing a president, which the framers deliberately made hard to do.

But if you dive a layer deeper, and read the debates over executive power that occurred in June, July and August 1787, it soon becomes clear that the framers were haunted by conversations that had occurred in that very same room 11 years earlier, in July 1776. The ghost at the banquet was George III.

Any robust expression of executive authority encountered bitter opposition as delegates conjured up memories of Julius Caesar, Oliver Cromwell and more recently, and ominously, George III. Edmund Randolph of Virginia developed a sizable following for insisting that the American executive must be a trinity, a three-man council instead of a single person, because all executive power tended toward tyranny, eventually dominating the legislative branch and transforming the office into a dictatorship.

As a result of these debates, if you read Article II of the Constitution, you encounter deliberately ambiguous language that makes it very difficult to know what a president could and could not do. He (not she) had some control over foreign policy with the advice and consent of the Senate, and was a potent force during a war as commander in chief, but otherwise resembled a merely symbolic figure. As the title suggested, a president should simply preside. The presidency of George Washington, more than the language in Article II, defined the powers and limitations of the executive branch for subsequent presidencies.

Fast backward to the summer of 1776, and you will discover the historical context for the anguished debates over executive power by the framers of the Constitution. The pivotal source is the Declaration of Independence, more specifically Thomas Jefferson’s indictment of George III for “the long train of abuses” that justified America’s withdrawal from the British Empire. Among the voluminous list Jefferson outlined: George III “refused his assent to laws” passed for the “public good,” “dissolved representative houses repeatedly,” “obstructed the administration of justice by refusing his assent to laws for establishing judiciary powers” and “made judges dependent on his will alone.”

This is the section of the Declaration that most Americans never read, preferring to focus on those magic words in the opening section, the words that begin “We hold these truths to be self-evident.” At the time, the delegates regarded those lyrical words as a merely rhetorical overture. They focused their attention on the later section of the document that we ignore. If we wish to understand what is at stake in the ongoing impeachment debate of President Trump, we need to recover the meaning of the words we have preferred to forget.

So please read them. Don’t be deterred by Jefferson’s references to political events of the previous decade you find unfamiliar. (If frustrated, look them up on Google.) What you are witnessing is the indictment of a king for behaving like a king; that is, presuming that he derives his authority from God, when in fact all legitimate authority is derived from the very people he regards as his subjects.

This passage constitutes a truly profound moment. In it, the tectonic plates of Western political thought shifted from a feudal to a modern location. Jefferson declared that all political power flows upward from the electorate rather than downward from a divine source. This was the monumental change that made the American Revolution a revolution.

In the new republican order, all political claims to omniscience were banned outright, all citizens were equal under the law, none are above it, and all elected officials, no matter how indispensable, were disposable. These are the core principles that made the United States the first nation-sized republic in modern history, and now the oldest.

Within the bright rays of light cast by this historical legacy, the core issue at stake in the current impeachment debate is the claim made by President Trump’s own lawyers. Trump’s chief offense is his own defense. Namely, that as president he cannot be indicted, convicted or investigated, and has no legal obligation to provide documents or witnesses when requested by the House or Senate. That means President Trump is claiming he is a elected monarch who is above the law.

The specific charges related to Ukraine, while significant, are only one example of a more abiding pattern of behavior that President Trump has never tried to conceal; indeed, his most devoted supporters find it beguiling; and his own lawyers have made it the foundation of his defense.

His authority is inherently sovereign. He is immune to any evidence that does not accord with his personal agenda. He sincerely regards the infamous conversation with the President of Ukraine as “perfect.” He cannot lie because no empirical foundation for truth is permissible other than his own self-interest. He is cognitively wired to think like a divinely inspired king.

Armchair psychiatrists can speculate on the source of this syndrome. More relevant for our purposes, and for the looming trial in the Senate, are the legal and historical consequences if, as appears likely, President Trump is acquitted.

His defenders can argue that his behavior, while disconcerting, does not rise to the level necessary to remove him from office. They can also claim, quite plausibly, that his imperious style was on full display throughout the 2016 campaign. Voters knew what they were getting, and he won the majority of electoral votes. He should not be convicted for being who he is and always was.

More legally minded critics, most concerned about damaging the hallowed framework of the Constitution, can argue that President Trump’s acquittal would effectively surrender the role of Congress as a coequal branch of government. James Madison is the guiding light of most legal scholars, and the Madisonian doctrine of checks and balances would be forever compromised if Trump’s behavior is endorsed.

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    More historically minded critics, and I fall within this camp, can argue that nothing less that “the spirit of ’76” is at stake. Betraying Madison and “the spirit of ‘87” is tantamount to acknowledging that we have lost our mind. But betraying Jefferson is tantamount to declaring that we have lost our soul. For in doing so we are siding with George III rather than Thomas Jefferson. We are saying that the American Revolution was a mistake. We are announcing that we are no longer a republic. And that, so it seems to me, is self-evidently a price not worth paying.