A Cabinet member, writing in his diary, complained that "one trouble" with the president "is that he becomes defiant when his friends are criticized." The defiant president wrote that his critics had made "fraudulent buildup of flyspecks on our Washington windows into a big blot or mess. For several years, the . . . opposition had tried to make a case against the administration, only to find that the administration was always alert in rooting out corruption or bad practices wherever they existed."

The Cabinet member was Interior Secretary Harold Ickes. The president was Harry S Truman, reflecting in his memoirs about Republican accusations of corruption. The charges stuck, sending high administration officials to prison and inflicting political damage on Truman. In 1952, the accusations became part of a Republican litany of "communism, corruption and Korea."

Ronald Reagan voted for a Democratic presidential candidate for the last time in 1948 when he cast his ballot for Truman. Years later, Reagan told me that he did not regret it. Long after he became a Republican and long before it became conventional wisdom, Reagan expressed positive opinions of Truman's courageous foreign policy decisions and of his "spunk," a quality that Reagan possesses in abundance.

When a crony comes under fire, Reagan reacts much as Truman did. "Truman angrily regarded attacks on any of his subordinates as attacks upon himself, which may have been true as far as it went, yet such a response was not a satisfactory one to allegations raised against individual officials," Truman biographer Robert J. Donovan wrote.

Last week, in an interview with The Washington Post, Reagan ran true to form when asked about the convictions of former White House aides and the current pursuit of Attorney General Edwin Meese III by an independent counsel. "I have a feeling that there's a certain amount of politics involved in all of this and I have a feeling that I'm really the target they would like to get at, and they are doing it by going after these other people," Reagan said.

It is certainly true that some of Reagan's partisan critics have politics in mind when they lump convictions, prosecutions, investigations and suspicions of administration officials into an encompassing "sleaze factor." But Reagan has made his administration an easy target by refusing, almost as a matter of principle, to condemn wrongdoing committed by a friend.

Like Truman, Reagan seems unable to comprehend the cost to his reputation of the easy acceptance of corruption. Perhaps this is because Reagan's personal integrity has always been taken for granted. He had a clean record as a two-term governor of California. Concerns raised by his critics when he was running for president were of competence or ideology, not of ethical behavior. How is it that the "sleaze factor" has become a Democratic battle cry in 1988?

One of several possible answers is that the Reagan administration is suffering from the accumulated ethical debris of two terms. People who stay in office too long, or at least the people who work for them, are apt to think that they can get away with anything. The ethical problems of the Truman and Reagan presidencies, and many others, piled up in the homestretch.

The principal deficiency in the Reagan presidency has been the absence of proclaimed ethical standards. Reagan should take the blame for that. He is not shy about using the White House "bully pulpit" to make moral judgments, yet he has said almost nothing about standards that he expects subordinates to uphold. One can search Reagan's speeches without finding the equivalent of Grover Cleveland's famous pronouncement that "a public office is a public trust." Each Reagan official has been allowed to decide for himself what is ethically appropriate.

Seen through the mists of history, the ethical deficiencies of Truman's presidency are overshadowed by significant foreign policy accomplishments. Historians may reach a similar judgment about Reagan, particularly if he stays on course on arms control. But it is sad to see the president dismiss serious charges of corruption as simply political concoctions of his adversaries.

Reaganism of the Week: Asked in The Post interview Thursday whether the huge federal budget deficit would be a burden for future generations, the president said: "Well, it's a burden . . . but, at the same time, it is not the disaster some people proclaim."