Let's hope that James Whitmore never decides to do a one-man show on Calvin Coolidge.

In "Will Rogers' U.S.A.," now at Ford's Theatre, he does Rogers doing Collidge - after saying that the accomplishments of the Coolidge administration could be written "on the head of a pin and still have room left over for two choruses of 'Yes, We Have No Bananas.'" But Whitmore, who has also done successful one-man shows on Harry Truman and Theodore Roosevelt, is such a fine actor that if he insisted on doing a full evening of Coolidge, it probably still would be worth seeing.

His skill is shown off at the beginning of "Will Rogers," when he enters as a fussy literary narrator and then takes off his tie, pulls out a neckerchief and turns into the character he has introuced. While our eyes are on the neckwear, he bows his shoulders and legs, rearranges his face from the jutting chin and beetle eyebrow look of his film priests into Rogers' wrinkled grin, and adopts a strange posture in which he seems to be loosely hanging from his own belt.

Another triumph is the way Whitmore takes Rogers' corn - and there's lots of it popping up in his field of folk wisdom - and extracts from its kernels of wit. The classic lines ("I'm not a member of any organized political party - I'm a Democrat") are easy. But while a delivery of apologetic chortling, he can bring down the house with a line like "Te Washington Monument is the only thing in this city that has a point to it."

The material of the show is all culled from Rogers' writings and shows. What he has to say about politicians and their conventions, American foreign relations, inflations, peace conferences, Indians' rights, even ecology, is startlingly apropos now. Only a rather tedious section making fun of women's corsets reminds us that his jokes are more than 40 years old.

"Will Rogers" also holds up remarkably well as a seven-year-old show - it played Ford's in 1970 and again in 1974 - now that the one-person evening has become a popular genre. In contrast to those heavy evenings when a famous character is made to recite his biography to us or to imaginary characters in the air, the Rogers shoe consists of audience-directed material, in which the personality of the man comes out naturally through his conversation.