Authors Arnold Stone and Donald Freed have an astonishing proposition to lay before us in "Secret Honor," a relentless and obsessive one-man drama in which a boozed-up Richard Nixon finally bares his soul by the flickering light of a late-night fire.

What, they are suggesting, if Watergate was not the downfall of the former president, but actually his crowning achievement? If the public scoundrel was really a private hero? If he actually engineered the ignominy of his final days to save us from the real power mongers, those right-wing plutocrats who are forever out to feather their nests at the expense of the republic?

Poppycock, you say. And you are probably right. The authors, after all, have taken the precaution of subtitling their work "A Political Myth." Whether or not you agree with their thesis, however, there's no denying the theatrical electricity generated by "Secret Honor," now playing a four-week run at the New Playwrights' Theatre. As portrayed by Philip Baker Hall -- seemingly with the assistance of a covey of invisible demons -- this Nixon is throbbingly alive.

He is also possessed, foul-mouthed, bigoted, vindictive, comically inarticulate on occasion and lethally blunt on others. When we first meet him in his book-lined study sometime in the 1980s, he is fumbling with a tape recorder, trying unsuccessfully to get it to work, so he can dictate his final testament to the nation. The image of the clown, all thumbs in his anger, is one we've come to expect from those who look less than fondly on the former president. But "Secret Honor" is not to be so simple an excoriation.

In 100 intermissionless minutes, Hall and the authors expand that image to embrace the impotence, the frustration and the loneliness that seethe in Nixon's heart. By the end, there is something oddly moving about this man who sold his soul to the devil and then in a last-minute burst of idealism, tried to reclaim it for himself. The devil is "The Committee of 100 and their buddies, the cowboys from Vegas and Phoenix and Houston," who, the authors maintain, masterminded Nixon's political career from the start, fueled the Vietnam war for their own profit and, indeed, would have seen to it that Nixon had a third term in office if he hadn't purposefully eliminated himself from their nasty game on what may be the biggest foul of all time.

I sense you are balking again and there's certainly no pretending that the authors are unaware of the outrageousness of their thesis. But you don't get that thesis right off the bat -- only tantalizing bits and pieces. Nixon may want to exonerate himself, but his heart is too full of enmity and despair to hew to rational argument. Indeed, as the liquor flows, he is like a drunken bumblebee, flitting from one poisonous plant to the next.

A portrait of Henry Kissinger on the wall sets him off on a scatological diatribe against the former secretary of state. The family Bible summons up maudlin memories of his childhood and his Quaker mother. In the same breath, his musings are apt to go from Helen Gahagan Douglas ("She was a strong woman, uh, noble-looking, uh, uh, beautiful is what she was . . . I liked her") to the savage cartoons "making me look like a g'damned tramp."

All the hurts of his life are still alive in his mind: the summer he had to work as a carnival barker and the years he served as Ike's "stinking caddy." Big betrayals and petty insults consume him equally, and he ricochets from one to the next, governed only by the mad logic of paranoia. Hall handles the demanding transitions with extraordinary dexterity, making them acutely funny at first, then unsettling and finally the pathetic measure of a broken man.

Something clever is going on here: Before "Secret Honor" lets you in fully on its political revelations, it draws you into a disturbed mind. By the time all the pieces of the authors' argument fall together, Hall has already won you over on purely theatrical grounds. I dare say it is entirely possible to reject "Secret Honor" as historical hogwash and still be seduced by his rampaging performance. You will, in fact, notice a remarkable transformation in the course of the evening. Although Hall bears scant resemblance to his subject, the fierce emotions slowly remodel his face and he actually seems to acquire the celebrated jowls and the dark shadow.

"Secret Honor" has been pruned and honed since it started out two years ago in a 38-seat playhouse, then occupied by the Los Angeles Actors' Theatre. The direction by Robert Harders is now tight as a screw and the production has acquired a handsome set, designed and expertly lit by Russell Pyle. But it is Hall you will want to see. Whatever your position on the political spectrum, the actor, erupting with a sardonic chuckle one moment and bloodless fury the next, will keep you on edge.

Secret Honor: The Last Testament of Richard M. Nixon: A Political Myth, by Donald Freed and Arnold Stone. Directed by Robert Harders. Set and lighting, Russell Pyle. With Philip Baker Hall. At the New Playwrights' Theatre through Feb. 2.