TEXAS. By James A. Michener. Random House. 1,096 pp. $21.95.

THERE'S SOMETHING inarguable about James Michener. Five years ago the then-governor of Texas, William P. Clements, invited him to come down and write a mega-book timed for the Texas Sesquicentennial in 1986. In a state famous for hating Yankee authors (Edna Ferber had Texas in a frenzy for years over Giant), Michener succeeded in making himself a well-loved figure before he had published a word. The legislature and the Texas Institute of Letters honored him; the multi-millionaire establishment clasped him unto its breast. The University of Texas gave him extensive free office space and research assistance. He was photographed wearing a cowboy hat, and quoted on his love of Texas. He bought a house in Austin and announced it would become his ermanent home. Now, five years later, here's the book, impeccably mega both in its bulk and commercially -- the first printing is 750,000, and the mini-series is already in the works. One's first impulse is to stand in awe of the whole gleaming enterprise.

It is, like most of Michener's work, a sweeping panorama of regional history done in the form of a novel. Michener came up with his formula before the word "novelization" had been invented, but it fits his work quite well: this is a novelization of Texas history. In his words, it "strives for an honest blend of fiction and historical fact." When it's time to recount the story of the battle of the Alamo, for instance, he invents a handful of characters on both sides and has them engaging in dialogue with Jim Bowie, Davy Crockett, and General Santa Anna. In the grand design of the book, the governor convenes a five-member task force to study Texas history for the sesquicentennial, and its talkymeetings are interspersed in a narrative that traces all its members' family histories.

Texas history is in some ways an ideal Michener subject. Because it is largely separate from the mainstream of American history -- its roots are in the Spanish empire, not English colonization -- it's still an unfamiliar subject for most people. And the mythic quotient is probably higher than New England's. There's Cabeza de Vaca wandering in the wilderness naked for seven years, Coronado's search for the seven cities of Cibola, missions, murderous Comanches, separate nationhood, trail drives, the Civil War, the cavalry, Sam Houston, oil . . . for a historical novelist, Texas is pretty near a can't-miss proposition. Michener, who has good news sense, gives only a light once-over to the most familiar Texas subjects -- there's very little on cowboys -- and gets a lot of mileage out of the underpublicized Spanish-Mexican side of Texas history, and out of the non-western part of the frontier.

As light history, it's pretty good. Everyone is entitled to a theory as to why of all American writers Michener is the most popular, and mine is that he appeals not only to our desire for melodrama but also to our practical side -- he crams his books with facts, so that one may feel that the long hours spent reading one qualify as self-improvement. As a novel, though, its only real virtue is some degree of yarn-spinning power. The many characters aren't one-dimensional, but they're two-dimensional: brave yet headstrong, kind yet lazy, etc. (though all members of minority groups tend to be just plain good). None of them stays in mind as embodying the complexity of real life.

The reason is not exactly a lack of art on Michener's part; it's more that the form dictates that everything novelistic must be in the service of delivering history. Nothing ever happens that doesn't embody an important trend. We meet a young boy in Mexico in the early pages; soon we learn that he "was one of the first of Mexico's mestizo children, half Spanish, half Indian, that durable breed which even then seemed destined to take over Mexico and remote Spanish territories like the future Texas," and then he's off to join Coronado's expedition. When Michener wants to tell us about Texas' five geological zones, he has to say, "Ludwig Allerkamp . . . saw, for example, that this central part of Texas consisted of five clearly defined strips, each a minor nation of its own." Because this book couldn't in good conscience fail to mention the pecan pie, he has another character invent it. The meetings of the governor's task force are mostly devoted to sermons by professors, another way of shoehorning material into the novel form. While it's hard to argue with success, it seems Michener's natural gift would be at a kind of informal narrative history, and forget translating every thought into a worked-up line of dialogue.

That's a problem generic to Michener; there's one other problem for this book in particular. Michener is one of the last of the good liberals, a gentle, Quaker-educated man. Texas in its dominant strain is not liberal at all -- it's tough, practical, prone to violence, worshipful of money. To Michener's great credit, he grapples earnestly with the Texas character in a way that Texas' own writers often don't, and convincingly roots it in the experience of the early white settlers from the mid- South. He correctly points out how poor and uncivilized Texas was for so much of its history. But he just doesn't seem to be able to work up much genuine feeling about Texas as it is now. The romantic past captivates him; the year 1900 doesn't arrive until page 825. He pretty much skips the '30s, '40s, '50s and '60s, and in the '80s he tends to be suitably awed by his businessman-characters' big deals but to grant them redemption only by giving them sneaking liberal sentiments. He has enough gumption to chide, but he's too nice to use anger or outrage as the center of a book. So inside the impeccably constructed big-book edifice is a hollow spot. I wonder if anyone will notice.