THE 2 OF THEM : NANCY REAGAN; The Unauthorized Biography <i> By Kitty Kelley (Simon & Schuster: $24.95; 603 pp., illustrated)</i>

What sort of madness has seized the publishing world? Nancy Reagan reputedly got $3 million for her nagging memoirs. Ronald Reagan is said to have been paid the incredible sum of $8 million for a collection of his speeches (hey! there’s something you’d want to curl up with!) and some ghosted sludge called an autobiography. And here comes Kitty Kelley with her profile of Nancy for a rumored $3.5 million.

Putting aside my natural bias against books in the lottery bracket, I must praise “Nancy Reagan: The Unauthorized Biography” for giving the publishers finally what they expected and paid for: super-cattiness. Kelley can always be depended on to deliver not only the cat but a very big load of used kitty-litter.

The Reagans and their friends are denouncing the book as all worthless trash. But it isn’t. It may be one-sided, and Kelley may have been too hospitable to grudge quotes, but there’s enough soundly researched material here to make this a reasonable question: Can a woman get to the very top of our society simply by building a career around the right proportions of promiscuity, infidelity, greed, duplicity, arrogance, abuse of her children, henpecking of husband, browbeating of subordinates, and a lot of sticky self-pity?

Nancy Reagan did, says Kelley, but to be fair, she allows as how it may have all started with childhood insecurity.

Nancy’s mother, Edith Robbins, was a foul-mouthed high school dropout who deserted Nancy’s father (and for five years deserted Nancy, too) to go into show biz, and, when she saw her career waning, snagged a Chicago neurosurgeon named Loyal Davis and began social climbing.

Mama’s old theater buddies helped Nancy get started in the business, and Nancy (Kelley tells us with relish) did the rest with her talents on the casting couch. After she had had several heavy dates with Clark Gable, sometimes known as the Bull of the Metro Lot, the word went around and the quickie beaux began knocking on her door.

Among them, saints be praised, was none other than Benjamin Thau, head of casting for Metro-Goldwyn-Mayer. Could a sweet graduate of Smith College (class of 1943) ask for any better luck? So long as they were sleeping together, Nancy got roles, though never very good ones. Most of the people around MGM agreed with Spencer Tracy, that Nancy “projected all the passion of a Good Humor ice cream--frozen, on a stick, and all vanilla.”

Reduced finally to doing bread and soap advertisements, she knew it was time to snag a provider. Enter Ronnie.

Still rebounding from being divorced by Jane Wyman, Ronnie was mooning around, trying to forget her by bed-hopping. He wasn’t always nice to his girlfriends. One told Kelley that he date-raped her. Another complained that when she informed him that she was pregnant, he told her to take a walk.

Nancy was luckier. When she announced her pregnancy, Ronnie married her--though weepily confiding to another old flame that he felt he had been trapped.

As it turned out, Ronnie got along with his in-laws beautifully. He loved to sit around swapping dirty jokes with Edith, while Dr. Davis--who was a John Bircher, loathed blacks and Catholics, and couldn’t even bring himself to use the word Jew--patiently converted Ronnie from a liberal Democrat to the right-wing fantasizer we know so well.

Hereafter, Kelley takes us down a familiar road--from Ronnie’s propagandizing job for General Electric to the big bucks and blarney that carried him to the White House and beyond--and I would refuse to travel those ruts again if Kelley hadn’t brightened the journey somewhat by emphasizing the part played by ruthless Nancy.

We’re told that she was particularly cruel to her children. She had as little as possible to do with the two (Maureen and Michael) from Reagan’s first marriage, and sometimes pretended they did not exist. When daughter Patti was a child, Mrs. Reagan would sometimes smash her in the face with a hairbrush for punishment, says Kelley, and later Patti was disinherited because she wasn’t straight-laced enough to suit Mama.

But if Nancy hated to mother her children, she loved to mother Ronnie. She treated him as a child, says Kelley, even to the point of interrupting meetings in the White House to tell him to go take a bath.

Kelley claims she got the material for this biography through a thousand interviews with Mrs. Reagan’s intimates and relatives and employees, and with those paid to watch the famous.

I question the genuineness of some of the information passed on to her. For instance, we learn that shortly after President Reagan was shot, Frank Sinatra visited Mrs. Reagan in the White House, and afterwards he told some barroom pals that she had greeted him with “Frank! Thank God you’re here. There’s finally someone I can tell my dirty stories to!” I don’t doubt that Sinatra said it; he’s enough of a rat to make up a story like that about a lady friend. But I do doubt that Mrs. Reagan said it; it doesn’t even begin to fit into the prissy profile that Kelley gives us. Edith might have said something like that, but not Nancy.

My faith in Kelley’s research only increases my puzzlement as to why so much of this biography seems lackluster. It sorely needs the stuff her lawyers made her leave out. What remains often seems used. She tells us much more about the Reagans’ dependency on astrologers, for example, but the world has known of that since Don Regan’s memoirs in 1988.

Did the ferocious hype that preceded the book make us expect too much? Having read the front-page stories leaked to the press by clever publicists--about Nancy’s occasional dalliances with Sinatra when Ronnie was out of town, and about her recruiting Mafia-connected lawyers to settle a strike, and about her stingy recycling of gifts, and about her heartless refusal to pay for her grandmother’s tombstone or visit her dying father --these anecdotes seem stale when I encounter them again in the book.

After all, one can’t be lastingly titillated by the imagined scene of two naughty senior citizens making out, even if it is in the backroom of the White House. And I suspect it’s because Kelley feels a bit desperate to keep her readers hanging in there that she retells the sexual perversities of Alfred Bloomingdale, husband of Mrs. Reagan’s best friend. Not that I object. I would much rather read about Mr. Bloomingdale’s playing horsey with a whore he subsidized at $18,000 a month for 12 years than wade through another telling of Mrs. Reagan’s feud with White House Chief of Staff Donald Regan, which Kelley also gives us.

The trouble with this book is that it isn’t flashy enough to be great gossip, it isn’t thoughtful enough to be really spiffy biography, and it doesn’t lighten enough corners to be impressive history.

More subtlety would have been helpful. Clever though they are, after a while the snide remarks about Mrs. Reagan--”cold smile of a calculating automaton,” “acting like a Marie Antoinette windup doll,” “The Hairdo With Anxiety” --come so frequently that they begin to lose their snap.

But let’s be grateful for what we get, which includes the many vivid examples of Nancy’s fanatical dedication to imagery, as on that occasion when she maintained her frozen smile for the cameraman while the little boy she was hugging peed on her shoes. And Kelley adds welcome embellishments to the tale of how Nancy, with the help of her toady, Michael Deaver (“Nancy’s Nancy,” his many enemies called him), tried to seize control of the presidency during Ronnie’s last term, when, as Kelley puts it, “the President’s mind was closed for repairs.”

And we get a fuller account than the daily press gave of how Mrs. Reagan wasted taxpayers’ money (sometimes taking along two hairdressers, “in case one got sick”) and illegally mooched a million bucks worth of free gowns off the ritziest designers, and of how she betrayed the people she promised to help in the fight against drugs.

I left the book with a feeling of frustration. Surely, if the gods are not all asleep, someone as obnoxious as the Nancy Reagan we meet in these pages should be dealt some pain, but the closest we have to real suffering came on the day that a Washington Post reporter wrote that Mrs. Reagan’s “piano legs taper with unhappy abruptness.” Always sensitive about her thick ankles, Mrs. Reagan, after reading that, is said to have taken to her bed for two days.