The difference between the present Iran-contra hearings and the Watergate exercise of 15 years ago is that then some people were sorry for what they did, and now, nobody is. This according to Sen. Daniel K. Inouye (D-Hawaii), a member of the late senator Sam Ervin's Watergate panel and chairman of the Senate panel conducting the Iran-contra probe.

He hasn't seen a flicker of remorse in the present crew. Lt. Col. Oliver L. North, who turned the caucus room upside down in his six days on the stand, announced that his "only real regret is that I virtually abandoned my family for work during those years."

Nobody seems sorry for what happened except those citizens who prefer a more rational approach to government and a little "glasnost" in the execution of foreign policy. The public, disillusioned with President Reagan, has transferred its affections to a younger, uniformed version of him, someone equally airy with facts, careless of rules and sure that the commies are coming.

The promised outcome of the hearings, which differ from Watergate in other important respects (some deliberately sought by Inouye, a man who craves dignity, order and calm), is the reverse of what was expected.

The White House is emitting sighs of relief strong enough to send a balloon across the Atlantic. The president has been vindicated, or at least lost as the author of the catastrophe in a cloud of Rear Adm. John M. Poindexter's pipe smoke. The former national security adviser swore that he made the decision about diverting the Iranian arms sales profits to the contras and kept it a secret from Reagan. The right wing is screaming for pardons for him and North.

North has become a political figure of such magnitude that some politicians speak of him as a convention keynoter or a vice-presidential candidate. Vice President Bush is reckoned the biggest winner among the presidential hopefuls because North, in his testimony, gave him a profile in courage.

The hearings threaten to produce an even greater scandal: the revelation that the Constitution, which is being celebrated on its 200th anniversary, is of minor concern to the public. Ollie thinks that the president should have the say on secret wars and that Congress has no right to thwart him. A resolution of reproach to the founders could, in this climate, be in the making.

The backbreaking inquiry into White House wrongdoing seems to have turned into a referendum on lying. If the popular outpouring for North, who admitted repeatedly lying to Congress, is any indication, truth has gone down for the count.

They have forgiven him the traveler's checks, which came from funds of the "starving" contras.

Support for the contras has jumped 20 points in the polls. For five years, the public has opposed military aid, but in six days Ollie, of the moist eyes and cracked voice, converted millions.

Inouye understands the havoc, but calls it "unavoidable." During a break in the questioning of the totally unrepentant Poindexter, he said philosophically, "We had to call North as a witness. We were aware that he was very charismatic . . . {and} how successful he was in convincing wealthy people to open their wallets. Americans cheer and root for an underdog and he said he was going to be the scapegoat . . . the lieutenant colonel who was going to take the rap. There is a strong desire in this country for family, honor, duty, country and the uniform, and the colonel made a masterful presentation . . . . He was physically attractive, and although he made a few grammatical errors he was very articulate.

"We have a job to remind people of the Constitution and what it stands for," Inouye added.

The size of the joint committees worked for North. Inouye says he "presented a picture of one patriotic person confronted by 26 politicians."

Poindexter, North's boss, also raises doubts about how civics is taught at Annapolis. The admiral is driven by fear and loathing of the news media. The author of the "disinformation" campaign on Libya complains that the news media "overreacted" to the news of the president's sale of guns to Ayatollah Ruhollah Khomeini. "Congress reacts to the press," he said sternly, and caused the whole problem. Had he been in Philadelphia 200 years ago, there would have been no nonsense about freedom of the press.

History might have been different had he told the president last November that he authorized the diversion. But is he sorry? Not at all.

"I don't have any regrets for anything that I did," he said. "I'm not going to change my mind. And I'm not going to be apologetic about it."