THE WILLINGNESS TO FORGIVE and forget past sins is a peculiar American habit. Ask Richard Nixon, elected to the White House six years after giving a creditable impression of a psychotic in the wake of the California gubernatorial election.

Now, ten years after he drove off a bridge into Chappaquiddick's Poucha Pond drowning Mary Jo Kopechne, the decade's second most controversial political figure, Edward M. Kennedy '54 is hoping that we will forgive, and preferably forget, again.

When he wants forgotten is not minor. Much more than the actual crime, Kennedy's refusal to clear up once and for all what happened July 18, 1969 sticks in the craw. Ten years after, it still seems possible that the closest Kennedy has come to telling the truth was his confession to the people of Massachusetts that his crime was "indefensible."

Indefensible it certainly was--we don't know to this day the barest details of where Kennedy was going with Kopechne and what he did in the hours after the accident. His ten-years-after interview a few days ago did nothing to clear up affairs, Kennedy insisting that all the questions were answered during an investigation of which Kopechne's parents were highly critical.

But Kennedy's sins are apparently quite forgiveable. Americans insist today to the Gallups and the Harrisses that they believe in the Senator from Massachusetts; in poll upon survey upon test vote, they register their approval of his painfully obvious candidacy.

This is a paradox. Once, shortly after the fall from the bridge, most Americans said Kennedy should never run for President. Now they urge him to go after Carter, promising their votes.

Part of this change lies in Kennedy's performance since 1969. Perhaps, though it is hard to know, he has matured and sobered. Certainly he has worked hard and competently as a Senator. Another part of the solution may be that we are more cynical about the conduct of politicians--Watergate, Koreagate, Wayne Hayes, Daniel Flood, Charles Diggs and their ilk have increased our awareness of the moral failings of our leaders. A few years of such revelations have weakened the shock value, however.

But the more disturbing reason for the willingness to support Carter is that we are in a crisis and we care very little about the moral history of the man who promises to rescue us.

PRESIDENT CARTER HAS DIAGNOSED our "crisis of confidence" accurately. It's not that we don't trust Carter the man, it's that we don't trust Carter the leader. His Baptist morality is fine, but his energy program is a simpering excuse for real direction.

Because Ted Kennedy promises results, we don't stop to ask ourselves whether or not he lied to us, whether or not we can trust him as a man. We may be able to, but we're not even asking. His name helps him overcome Chappaquidick, but it wouldn't have been enough in 1976. It is enough now, because of our panic.

He seems to promise drive and success and an end to the aimless drifting Carter pathetically describes. If the price for that is a man who may not be personally forthright and trustworthy, we are willing.

That willingness is disturbing. Ted Kennedy's competence, not to mention his political stands, make him worth considering carefully for president. But some evaluation of Chappaquiddick should be part of that consideration.

Ted Kennedy, in part because he is a good Senator and in part because he is Jack's brother, seems to be a man with an answer. In our current fear, we have decided too quickly that an answer is better than a prayer.