The presidency; The Carter Presidency and Beyond, Power and Politics in the 1980s, by Laurence H. Shoup. Palo Alt: Ramparts Press, $11.95.

Shoup, a san Francisco-based political journalist with a bent toward expose, maintains that the "real" world is one in which politicians and political parties matter little. It is the corporate ruling class -- big business executives, "fat cats" financiers, media moguls, and influential private citizens -- that calls the domestic and foreign policy shots and runs the nation , he feels.

Among these sinister forces is the powerful and controversial Trilateral Commission, which, accoridng to Shoup, shapes both candidates and issues.

His detailing of the commission and "ruling class" influence on the CArter presidency is fascinating, though not persuasive.

Readers should look to other books to understand presidential politics and perhaps to Mr. Shoup for intriguing and entertaining, though not entirely credible, political scenarios.