TOO FUNNY TO BE PRESIDENT By Morris K. Udall with Bob Neuman and Randy Udall Henry Holt. 249 pp. $17.95

That Morris Udall is one of the good guys of American politics is a proposition I am ill-disposed to dispute, but it takes more than a good guy to make a good book. This is another proposition altogether, one that unfortunately is proved to a fare-thee-well by "Too Funny to Be President." Though it does have a moment or two in which it more or less lives up to its title, for the most part this is one of those books that would have best served author and reader alike had it gone unwritten and unpublished.

The chief problem with the book -- chief among many, alas -- is that Udall and his collaborators seem never to have decided precisely what kind of book they wanted to write, with the unhappy result that they have written several different books, none of which has much to do with any of the others. "Too Funny to Be President" is like one of those bizarre creatures one sees from time to time in political cartoons: part horse, part elephant, part sea lion, part ostrich, part rhinoceros -- all of which add up to a beast that can neither walk, fly, nor swim.

The authors begin with a commentary on political humor, illustrated with numerous anecdotes, too many of which will be too familiar to the political community that is likely to be the book's principal readership. They then switch, without a word of warning, to two chapters about Udall's record on environmental issues. Next, again without warning, we are given the author's personal and political autobiography. This is followed by several more chapters on political humor, connected to each other by no visible threads. Then, with 60 pages still to go, "Too Funny to Be President" suddenly turns into a joke book of the Bennett Cerf variety, with instructions about how to deliver punch lines followed by a 50-page compendium of jokes, only one of which, by my count, is funny. Since you were wondering, here it is:

"A professor teaching English told his class that the good story should work into the first paragraph, if possible, a reference to the deity, royalty, sex, and a touch of mystery. A student came back in a few minutes and said, 'I think I've got it.' His opening paragraph read: 'Oh, my God,' said the queen, 'I'm pregnant again. I wonder who could have done it this time.' "

The connection between that modest tale and politics has yet to be made, but perhaps it would get a chuckle out on the hustings, where listeners are desperate for comic relief after being socked $500 a plate for microwaved roast beef and California plonk. Perhaps they would also be amused by the politician who said, "My opponent deserves to be kicked to death by a jackass ... and frankly, I'd like to be the one to do it!" or by the constituent, irate over a proposed congressional pay increase, who wrote:

"Dear $2100 and wage freezer Morris Bastard Udall!

"If you and your bastards in Congress vote yourselves another fat pay raise plus benefits, I hope you get Cancer! I and my wage frozen friends will not pay or file any income taxes ... so help me God! You scumbags let food prices skyrocket while you silly ... live off the fat of the land! If you were paid hourly you would starve to death!"

But that, folks, is just about that. "Too Funny to Be President" proves nothing so much as that most political humor, like most humor of any category, is not really all that funny. What seems uproarious in a campaign speech or a Gridiron Club festivity emerges as stale and puerile when reproduced in print; as they say, you had to be there. Mo Udall is indeed a funny man -- and apparently an intelligent, honest and principled one as well -- but what comes across as wit in a banquet hall or on television loses much of its flavor when embalmed between hard covers.

In fact, when Udall stops heaving the one-liners around and pauses for serious reflection, his book gains both weight and interest. He's right that political humor is in decline -- "The ability to deliver a riveting speech, rich in substance, enlivened with humor and anecdote, is a dying art in Washington today" -- and that it is the politician with a sense of humor, or "inner equilibrium," who is best equipped to deal with the disappointments as well as the triumphs of factional conflict. In that regard he approvingly quotes Bob Dole's comment after being defeated for the vice presidency in 1976: "Contrary to reports that I took the loss badly, I want to say that I went home last night and slept like a baby -- every two hours I woke up and cried."