Still another hat in the election-year-fiction ring, as former LBJ Special Assistant Valenti (A Very Human President, Speak Up with Confidence, etc.) pulls out all the stops in an effort to out-weird yesterday's headlines. The centerpiece of this scenario: smart, handsome, liberal, well- connected Texas Vice President Bill Rawlins challenges his own battered President, Don Kells, for the nomination. After a few paragraphs of lip service to unfashionably hawkish Kells, virtually all the party faithful--from Rawlins's own reptilian advisor Hoyle Henderson to main-chance White House staffer Mike Carson--prepare to bolt, leaving behind only rugged Special Assistant Clem Barkley, elderly Sen. Gifford Gray, and Kells's personal friends. Meanwhile, new trouble for the reelection campaign: Somebody's leaked word of Presidential counsel Willacy Hughes's forthcoming secret diplomatic mission to China--a game effort to stand against the newly toughened Russian confederation by supporting the leaders of a recent Chinese coup--and the likely source, newsman Roy Hickey, has been killed by a pair of Bulgarian heavies with links to the KGB; the FBI's found classified documents and dope stashed in the apartment of Terry Geer, another Special Assistant; and the charming, treacherous V.P. indicates that the Russians are prepared to make big political concessions if he's voted in. All this would be worrisome if Valenti weren't the kind of political Pollyanna who thinks the bad guys always stumble over their own feet. The book's real agenda becomes clear before it even gets under way, in the Acknowledgments and list of characters, in which names are dropped with frantic abandon, like barrels tossed off a sinking ship. Valenti's view of politics is by no means as simple-minded as some notable Beltway insiders', but he's no match for Tom Wicker (see below).