Etched in history is President Gerald Ford’s unprecedented October 1974 appearance on Capitol Hill to explain why he pardoned Richard Nixon, his disgraced predecessor. Ford believed Congress and the American people had a right to know why he decided to absolve Nixon of any criminal charges related to the Watergate break-in and its cover-up.

His purpose in issuing the pardon, he said, was to “change our national focus” and shift attention “to the pursuit of the urgent needs of a rising nation.” Instead, he was severely criticized and lost his reelection bid two years later, in the closest electoral vote since 1916.

“Time has a way of clarifying past events,” Sen. Edward Kennedy (D-Mass.), an early critic of the pardon, later said, adding that he belatedly saw “that President Ford was right. His courage and dedication to our country made it possible for us to begin the process of healing and put the tragedy of Watergate behind us.”

We certainly do not need another “long national nightmare” like Watergate, as Ford characterized it. Yet that may well be exactly where we are headed unless President Donald Trump considers truthful cooperation to be an imperative. We certainly do not need more free-wheeling offensive comments or late-night invective tweets that are misleading and divisive.

The American experience is littered with scandals, questionable activities and misunderstood decisions by the executive branch that have thrust congressional and judicial inquiries to the forefront of American consciousness. When presidents have been unwilling to cooperate with an investigation, the resulting confrontation is often ugly and long-remembered, as the escalating Ukraine scandal undoubtedly will be.