When Richard Nixon announced his resignation 40 years ago, it was for one reason: Members of Congress had informed him that he would be impeached by the House of Representatives, convicted by the Senate and removed from office.

In retrospect, one of the most striking features of the Watergate controversy is the continuity between a pivotal decision of the founding generation and the judgment of congressional leaders more than 180 years later. In 1974, the nation's representatives focused on just the kinds of wrongdoing that prompted the founders to authorize impeachment in the first place.

Under the Constitution, the House of Representatives can impeach the president only for "Treason, Bribery, or other high Crimes and Misdemeanors." But an initial draft of the text, found in the official journal of the Constitutional Convention, was written in broader terms, allowing the president to be impeached for "malpractice, or neglect of duty" as well.

On July 20, 1787, this draft provoked a pivotal debate. One extreme position, with little support among the delegates, was that the legislature should have the power to remove the executive at its pleasure. The opposing position was that in the new republic, the president ought not to be impeachable at all.

The third position was that the president should be impeachable, but only for a narrow category of abuses — for example, procuring office by unlawful means or using his authority for treasonous ends.

A new draft of the Constitution's impeachment clause emerged two weeks later. It would have permitted the president to be impeached, but only for treason, bribery and corruption. In early September, the delegates took up the question anew. They slightly broadened the grounds for removing the president, but in a way that stayed close to the compromise position that carried the day in July.

The opening argument was offered by George Mason, who complained that the provision was too narrow and that "maladministration" should be added. But James Madison responded that the term "maladministration" was so vague as to be "equivalent to a tenure during pleasure of the Senate" — something the framers had been trying to avoid all along. Mason withdrew "maladministration" and added the more precise "other high Crimes and Misdemeanors." With minor changes, the impeachment clause was finalized.

With respect to Nixon, the first article of impeachment was based on the Watergate break-in itself — Nixon's unlawful effort to obtain political intelligence from surveillance of the Democratic National Committee. The second article involved Nixon's unlawful use of the FBI, the CIA and the IRS for political purposes. Both of these articles were tightly connected to the founders' concerns about corruption and efforts to gain or keep the office by unlawful means.

In recent decades, prominent people inside and outside Washington have called for impeaching both Republican and Democratic presidents for reasons that fall far short of these grounds. As we remember the painful events of 1974, it's worth honoring lawmakers' impressive fidelity to the Constitution.