RICHARD NIXON has really gone off the deep end. In a new play by Donald Freed and Arnold M. Stone, he spends his time in his study talking into a tape-recorder, defending his career before an imaginary judge. He claims that the multi-millionaires of California's Bohemian Grove--the real rulers of America's industry and military--put him in the presidency. He didn't really want to continue war in Vietnam or get involved in the Chilean counter-revolution, but rather those filthy moneymongers forced him to. Finally, sick of prostituting himself and his country, he resolved to stop being their puppet. As a result, they organized the Watergate scandal to boot him out of office. Nixon reveals all sorts of other things too--his dreams of being Abraham Lincoln, his childhood insecurities, his hatred of Kennedy. And when he's really raving, he spouts obscenities at the portrait of Kissinger on the wall, sings ditties at the piano, and cries to his dead mother for forgiveness.

All this information about this former president ought to be intriguing and provocative. But Secret Honor: Nixon's Last Tape is baffling and boring; a self-indulgent, sophomoric parody of a political figure who was actually very complex. The play's concept is amusing, but its unstructured, hour-and-40-minute monologue without intermission is sleep-inducing. Besides, Nixon (Philip Baker Hall) drops names and scandals in such an incoherent jumble that only someone minutely familiar with his career can grasp what is going on. Mixing facts and falsehood, he'll jump from the topic of Watergate to his first grammar school debate (he argued that girls were no good and won). What's more, he constantly interrupts his stream of jibberish, by raising his arms and launching into political rhetoric, by strewing papers around the room and slipping on them, or by going into prayer.

In their "political myth, "Freed and Stone create a flat and unoriginal character. This peevish politician is just another "hard luck kid" who developed a complex because he played second fiddle all his life--to his big brother, to Eisenhower, to Kennedy. At the end of the play, he reaches for the apron strings of his Quaker mother, whining "Mama, tell me what to do." He's the typical wimp who has cracked under pressure and now suffers under the delusion that he was really a hero who preserved his "secret honor."

AT ONE POINT Nixon complains to the judge: "You know the cartoons with the stubble and the jowls--do you realize that I have feelings too?" And in many ways the writers of the play themselves are cartoonists who place Nixon in the most humiliating light possible and mock him; theirs is the mentality of postcards that show a bald Reagan in nothing but his sweatsocks. At the beginning of the play, Nixon spends 10 inept minutes hemming and hawing the words "Testing: one, two, three...uh...uh...four," while fumbling with a tape that keeps blasting out the Goldberg variations. Nostalgically, he reminisces about all the dopey things he loved to do as President. These memories include sitting at his desk "with the fireplace running and the air-conditioning on" and inviting over Redskins stars on the white phone while discussing bombing Cuba with Kissinger on the red phone. Insanely, he tells his microphone how after Watergate the press and the liberals ate him alive--" an army of Ralph Naders and Jane Fondas and Jews and Redskin rats." Holding a gun to its metallic head, he screams at it: "And they'll come after you too!"

Although this tiresome monologue isn't much of a play, Philip Baker Hall does his best with the material and puts in a good performance as Nixon. With his deep, grumbly voice, he sounds like Nixon; with his long, flabby nose, brushed-back strands of greasy hair, baggy eyes and big ears, he looks like Nixon. Despite a tendency to slur his words, Hall delivers his lines as if he is truly absorbed by his train of thought, as if he has convinced himself that what he is saying is actually the truth. Unaware of his character's absurdity, Hall's Nixon compulsively unburdens himself of his guilty pleas and wild excuses.

But the audience gets no real sense of the man or the era. Nixon's confession is so warped and garbled that it is easier to dismiss his ideas than to digest them or speculate on their political or psychological significance. We can't even feel sorry for Nixon, because essentially, he is just a caricature.