Two people hold signs that read "Traitor" and "Treason Weasel" during a protest outside the White House in Washington, July 17, 2018. Credit: Andrew Harnik | AP

A few days ago, John Brennan, former director of the Central Intelligence Agency, tweeted as follows:

“Donald Trump’s press conference performance in Helsinki rises to & exceeds the threshold of “high crimes & misdemeanors.” It was nothing short of treasonous.”

Tweets should not be expected to capture the nuances of constitutional law. But a lot of people have been reacting along Brennan’s lines. It’s important to put his comment in context. As it turns out, it contains a major mistake — but it also raises a legitimate question.

The Constitution states, “Treason against the United States, shall consist only in levying war against them, or in adhering to their enemies, giving them aid and comfort.” That is an exceedingly narrow definition. “Enemies” are nations with whom we are at war (whether declared or open).

The United States is not at war with Russia. People who are alarmed by President Donald Trump’s statements in Helsinki are of course entitled to use the word “treasonous” in the colloquial sense — but not in the constitutional sense.

[Opinion: Why the Founders feared foreign influence in American politics]

The Constitution allows the president to be impeached and removed from office for “Treason, Bribery, or other high Crimes and Misdemeanors.” As the debates during the founding era make clear, egregious misconduct can count as a “high Crime and Misdemeanor” — even if it is not a violation of the criminal law.

During the constitutional convention, James Madison saw impeachment as a provision “for defending the Community agst. the incapacity, negligence or perfidy of the chief Magistrate.” He added that the president “might pervert his administration into a scheme of peculation or oppression. He might betray his trust to foreign powers.” It was clear that Madison believed these to be sufficient grounds for impeachment.

Gouverneur Morris, who originally opposed the idea of impeachment, added that the president should “be impeachable for treachery” (a broader concept than treason). He added, “Corrupting his electors, and incapacity were other causes of impeachment.” His crucial, soaring words: “The people are the King.”

Also at the convention, Edmund Randolph summarized the grounds for the impeachment clause: “The Executive will have great opportunitys of abusing his power.”

In “The Federalist Papers,” Alexander Hamilton similarly referred to “the abuse or violation of some public trust.” He argued that high crimes and misdemeanors “are of a nature which may with peculiar propriety be denominated POLITICAL, as they relate chiefly to injuries done immediately to society itself.”

[Opinion: Has Trump violated his oath of office? A primer on presidential duty and accountability]

Importantly, the founding generation did not want impeachment to be a partisan affair, or a means of undoing the outcome of an election. They recognized the gravity of any effort to remove a sitting president. Consistent with their goals, we do well to adopt a firm principle of neutrality.

For those who think, with Brennan, that impeachment is worth contemplating, it is necessary to ask: Would you think the same thing, if you agreed with the president on matters of policy, and thought that he was doing a wonderful job?

For those who think that the very idea of impeachment is ridiculous, it is necessary to ask: Would you think the same thing, if you did not vote for the president, and thought that he was driving the nation into a ditch?

It is not easy to argue that a performance at a press conference, standing by itself, can be counted as a high crime or misdemeanor in the constitutional sense. But Brennan was right to be alarmed by Trump’s shifting, ambivalent reactions to the findings of his own intelligence community; by his apparent deference to Vladimir Putin; by his obvious reluctance to condemn foreign interference in American elections by Russia.

It may not yet count as “perfidy” — but it’s gotten uncomfortably close to that neighborhood.

Cass R. Sunstein is a Bloomberg Opinion columnist. He is the author of “The Cost-Benefit Revolution” and co-author of “Nudge: Improving Decisions About Health, Wealth and Happiness.”

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