So the truth -- the good, the bad and the ugly -- is finally emerging. We are told that President Reagan, from the very start, approved weapons sales to Iran as a straight arms-for-hostages deal.

In a dramatic moment many had been anticipating, former national security adviser John Poindexter broke months of silence to tell the Iran-contra panels that he destroyed the secret document bearing Reagan's signature as the scandal was coming to light last fall to spare the president political embarrassment.

In that stunning revelation, Poindexter confirmed our worst thoughts -- the thoughts many of us hoped would not be confirmed. For out of the morass of self-serving statements and tiptoeing politicians, a truth has emerged.

And in that moment, all the excuses Reagan had been making for himself and many Americans had been making for him evaporated.

Less than a year ago, President Reagan said, "We did not, repeat, did not, trade weapons or anything else for hostages; nor will we." And even four months ago, he was claiming only that the deal had "deteriorated" into one that was tantamount to trading arms for hostages. But all Reagan said is untrue, if we are to believe his former NSC adviser.

Now it will be difficult to view him as the genial, wisecracking, slightly forgetful father figure. The facade has cracked. The ugly truth is that there was a deliberate and calculated attempt to evade the Constitution.

Most shocking about Poindexter's confirmation of Reagan's role was that the decision was discussed, even documented, coldbloodedly . What makes it even more despicable was President Reagan's frequent statement of his unwillingness to trade arms for hostages, his degrading of other countries that do, and his whipping of the American people into a frenzy against terrorism when he was secretly giving Iran weapons to pursue its terrible ends.

If, as Poindexter said yesterday, the president was not aware of the diversion of funds to the Nicaraguan contras, then he never was aware of at least half of the sorry story. But the half he knew about is bad enough. And there probably are fewer left in this country who would not believe he was also aware of the diversion of the funds. Indeed, the implication that the president did not know about the diversion requires a leap of faith in his credibility that few Americans should be willing to make now.

Before Poindexter's testimony, we heard six days of mean-green-marine-machine patriotism, something that appeals to the primordial nature of many Americans. Indeed, day after day, Lt. Col. Oliver North gained an increasingly strong emotional stranglehold on many Americans as he cleverly projected himself as a brave, America-loving Marine who put the nation's interest above that of even his family. Unfortunately, the panel members let North get away with his rhetorical ramblings on the failures of the Congress and the glories of the contras -- in part because of their failure to interrogate him properly.

Despite North's appeal, a recurring question kept nagging at me: Was the president a party to setting up a private foreign policy operation and thereby subverting several articles of the Constitution, or was he one of the biggest ignoramuses to occupy the Oval Office in many years?

Now we have heard the answer, and it is particularly galling, even frightening, in this 200th anniversary year of the Constitution: He was a party to setting up a shadow government in direct opposition to Congress, policies of the United States, and the oath he took to see that the laws were faithfully executed. Indeed, the fact that Ollie North is his spiritual son may be based on their shared disdain for the Constitution.

But with Reagan's oath came a responsibility, one that we learned yesterday beyond a shadow of a doubt that he failed in many respects to uphold.