BUSH-ISMS: President George Herbert Walker Bush in His Own Words compiled by the editors of the New Republic (Workman: $4.95, illustrated). President Bush's statements limp across the page, as if their crippled clauses had been injured in accidents and never quite healed. It's fun to imagine a sophomore English teacher reading this hilarious, snide compendium and trying to diagram such mal mots as "I think in politics there are certain moral values. I'm one who--we believe strongly in pluralism . . . but when you get into some questions there are some moral overtones. Murder, that kind of thing . . . " But it's disturbing to realize that these fractured phrases reflect the thought process of the leader of the most powerful nation on Earth. Despite an Ivy League education that must have included basic grammar and syntax, the chief executive has conceded he has problems with what he might term "the English Language Thing": "Fluency in English is something that I'm often not accused of."