We still do not know what hold Vladimir Putin has on Donald Trump, but the whole world has now witnessed the power of its grip.

Russia helped Donald Trump into the presidency, as Robert Mueller’s indictment vividly details. Putin, in his own voice, has confirmed that he wanted Trump elected. Standing alongside his benefactor, Trump denounced the special counsel investigating Russian intervention in the U.S. election—and even repudiated his own intelligence appointees.

This is an unprecedented situation, but not an uncontemplated one. At the 1787 convention in Philadelphia, the authors of the Constitution worried a great deal about foreign potentates corrupting the American presidency.

When Gouverneur Morris famously changed his mind in favor of an impeachment clause, he explained his new point of view by invoking a situation very similar to the one now facing the United States:

Our Executive was not like a Magistrate having a life interest, much less like one having an hereditary interest in his office. He may be bribed by a greater interest to betray his trust; and no one would say that we ought to expose ourselves to the danger of seeing the first Magistrate in foreign pay without being able to guard [against] it by displacing him.

The United States was then a comparatively poor and vulnerable country, so the Founders imagined corruption taking the form of some princely emolument that would enable an ex-president to emigrate and—in the words of Charles Cotesworth Pinckney—“live in greater splendor in another country than his own.” Yet they understood that even the most developed countries were not immune to the suborning of their leaders. As Morris said, "One would think the King of England well secured [against] bribery … Yet Charles II was bribed by Louis XIV.”