The outer Mongolian is not a Tartar but a mongoloid, a victim of the Down's syndrome, or as they refer to themselves, -- a glork -- one Waldo Benjamin who seems to be as quiet and happy and uncomplaining as they usually are. Even so his parents for the good of everybody (particularly themselves) send him away to Shady Glen with others with that ""haploid"" extra chromosome to be brought up with his own little extended family. Before very long -- in fact before he's four -- he's reading everything in sight and this special child proves to be extraordinary as a genius-manipulator, conning his way back home where he writes a forged check and starts his career in the stock market. Making a clean two million he pumps it into all kinds of causes -- good ones -- benevolent, scientific, political -- ending the war in Vietnam which he expects he will have accomplished (he dies at this point) by seeing that Richard M. Nixon is elected. . . . Mr. Slavitt is an easy, versatile, and always original scenarist and he has managed to overcome what might appear to be a precarious handicap; his Down's child is anything but a downer and he has managed to parlay medical sport into contemporary satire with geniality and casual bravura even if our local Stanford-Binet, the bestseller list, will probably find he's not much of an overachiever.