Unless I am sorely mistaken, Jhan Robbins' slim volume about the Trumans will be a favorite with gift-givers this year. Truman has become everybody's favorite president, and it is generally taken for granted that he and his Bess were the happiest couple to occupy the White House. One would expect their story to be a pleasant one, and it is.

It was, for example, lifelong. In his 85th year President Truman told an interviewer, "She had golden curls. And has to this day the most beautiful blue eyes. We went to Sunday school, fifth grade through high school in the same class, and marched down life's road together. For me she still has the blue eyes and golden hair of yesteryear."

Throughout his public life he delighted in calling her "the boss" and insisted that he discussed everything with her and sought her advice. They were "Bess and Harry . . . friends, lovers and political comrades," says author Robbins, and his book is for the most part about Bess herself, "who obstately selected a most unlikely man, tenderly and skillfully helped him to the White House at a most historical moment and treated it all like a pleasant bridge game, well played and nicely won."

If this description of Mrs. Truman's influence is taken at face value we are all in her debt, but the historicallyminded reader will find little substantiation for it. The author had no such source as the treasure trove of private letters which in a recent biography revealed the surprising extent of Clementine Churchill's influence on her husband. And Bess Truman herself was responsible for that. The story is that when the aghast ex-president happened to find her burning all his early letters to her and adjured her to "think of history," she replied enigmatically, "I have." She was always a very private person and insisted on remaining so.

The author has relied on the hearsay of contemporaries, and most of them support his view of Bess' role. In the days when Harry S. Truman was accepted in Washington as one of the Senate's inner circle, a "senator's senator," the wife of a Republican senator told a reporter: "Usually a wife is accepted on her husbands merits but the truth is Bess was 'in' before he was." Missourians of long acquaintance give instances of her help in his early compaigns and Victor Messall, his Senate secretary, gives Bess Truman credit for the idea of the famous whistle-stop campaign which had so much to do with Truman's election to the presidency in his own right in 1948.

"Bess sat in on most of the policy-making sessions and offered suggestions that Truman constantly included in his speeches. In addition she served as a one-woman Gallup poll and audience-reaction tester, keeping a sharp eye and ear on the crowds which listened to her husband's oratory.

Since the Trumans made it a rule to have a private conference every day, there seems reason to believe that she was privy to his decision to drop the atomic bomb on Japan. "White House servants recalled that the night before the dropping of the second bomb . . . Bess and Harry remained in his office for their nightly council much longer than the usual period. 'When they came out at last . . . they both looked real serious . . . didn't say a word, just looked straight ahead . . .'" And Truman told at least one reporter that he had consulted Bess.

No one can understand their relationship unless he or she understands the world that molded them -- a world almost as exotic and far away in terms of today's social mores as is their story. It was a world in which American women accepted the fact that their destiny was to be accomplished through their men but also a world in which women set the standards and established many of the traditional network which, as social historians point out, served to strengthen and undergird the whole society. It was the world of the free and open American girlhood of which De Tocqueville remarked and which Henry James celebrated in "Daisy Miller." For girls thought of as remarkable by their contemporaries, this girlhood was often prolonged. Elizabeth Wallace Truman was such a girl.

Independence was surprised, like the rest of the country, by the Truman victory in 1948, but it had been even more surprised by the Truman marriage 28 years earlier, according to author Robbins.

"We thought the wedding would never come off," said Matilda Brown, their high-school English teacher. "Not that they didn't seem to love each other, but hardly ever have such extreme opposites wed. Bess was rich, pretty, athletic -- a tennis champion -- with fine breeding. Harry was much further down the social scale, wore heavy glasses because of very weak eyes, didn't engage in sports, was such a voracious book reader that some considered him a sissy . . . "

Perhaps the definitive word on the two is that of Margaret Truman Daniel, the daughter who was the acknowledged apple of their eye: "After years of extremely close observation I've come to the conclusion that my father had to be exceptional. What other kind of man would an exceptional woman like Bess Wallace have chosen for a husband?"