There are a lot of misconceptions about impeachment. Incompetence isn’t impeachable. It’s terrible for a president to violate the oath of office, but doing so is not, by itself, an impeachable offense. Even posing a danger to the American people isn’t a legitimate basis for impeachment.

Under the Constitution, what is necessary is a “high crime or misdemeanor,” meaning an egregious abuse of presidential authority. Some crimes would not count; consider shoplifting or disorderly conduct. An action that is not criminal might be impeachable; consider a six-month vacation, an effort to jail political enemies or an abuse of the pardon power (by, for example, pardoning associates who have engaged in criminal activity at the president’s behest).

If you want to understand what counts as impeachable, read the Declaration of Independence. The Constitution’s impeachment provisions were written against the background set by the Declaration.

Read against that background, one thing becomes blindingly obvious: If the president has clearly committed an impeachable offense, the House of Representatives is not entitled to look the other way.

Impeachment is the mechanism by which “We the People” are supposed to be protected against such abuses as treason, bribery or systematic violation of civil liberties. In the face of such abuses, the House is not permitted to decide that because of political considerations, it will stay its hand.

It is not yet clear what happened during a July 25 telephone conversation between President Donald Trump and Ukrainian President Volodymyr Zelenskiy. It has been reported that Trump repeatedly pressed Zelenskiy to work with his personal lawyer, Rudy Giuliani, on an investigation into largely discredited allegations of misconduct by former Vice President Joseph Biden and his son, Hunter Biden. It has also been suggested that Trump reviewed and reassessed foreign aid to Ukraine with the specific goal of pressuring Zelenskiy to undertake that investigation.

Viewed in the light of the founding period, these are grave matters. At a critical moment during the Constitutional Convention of 1787, Virginia’s George Mason drew a direct link between the impeachment provision and presidential selection:

“No point is of more importance than that the right of impeachment should be continued. Shall any man be above Justice? Above all shall that man be above it, who can commit the most extensive injustice? … Shall the man who has practiced corruption & by that means procured his appoint in the first instance, be suffered to escape punishment, by repeating his guilt?”

An effort to press a foreign government to investigate a political adversary and his son is a uniquely horrific constitutional wrong. It is a violation of civil liberties as well as democratic processes. In Massachusetts, where the American Revolution began, defenders of the proposed Constitution saw a clear connection between the impeachment power and protection of freedom: “Thus we see that no office, however exalted, can protect the miscreant, who dares invade the liberties of his country,” wrote a pseudonymous author (probably James Sullivan, under the name “Cassius”) in the Massachusetts Gazette on Dec. 21, 1787.

If Trump did use foreign aid as a mechanism for pressuring Ukraine to investigate a political adversary, the constitutional answer is clear: He committed an impeachable offense.

If he did not use foreign aid for that purpose, but merely (merely?) pressed the nation’s president to work with his personal lawyer to investigate Biden and his son, the answer is almost equally clear. It’s an egregious abuse of authority for the president — who has a lot of leverage over economically dependent allies, including Ukraine — to ask foreign leaders to initiate an inquiry into alleged misconduct by a potential political opponent.

It’s important to note that reports about conversations between Trump and Zelenskiy are merely that. Because of their seriousness, the House is right to investigate them — and to do so in a way that respects the office of the presidency and the millions of Americans who voted for Trump.

For Democrats, of course, it’s tempting to focus on political considerations, above all the 2020 election. No one can rule out the possibility that from the Democratic point of view, impeachment might prove counterproductive.

In a constitutional gray zone in which it’s not clear whether presidential misconduct rises to the level of a high crime or misdemeanor, elected officials are entitled to exercise their discretion. They can stay their hand. But if a president has committed an unambiguously impeachable offense, political considerations are not supposed to matter.

If you’re doubtful, you might consider the words of James Madison, a driving voice behind the impeachment provision and the Constitution as a whole. During the lengthy debate at the Constitutional Convention on July 20, 1787, Madison noted that the president “might pervert his administration into a scheme of peculation or oppression.” Speaking just 11 years after the signing of the Declaration of Independence, he feared that presidential “corruption” might be “fatal to the Republic.”

Madison did not use the word “fatal” very often, and he never used it lightly. It’s worth keeping that word in mind.

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

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