Veteran political journalist Asbell spent the better part of a year tailing Senator Edmund S. Muskie from his headquarters in the Old Senate Office Building (known as the old S.O.B.), to his Capitol ""hideaway,"" to the many meetings he attends as chairman of the Environmental Pollution Subcommittee. He did it not to peer into the senator's soul but rather to better comprehend the ineffable realities of life in the Club of One Hundred. Asbell's stint in the slippery corridors of power turns out to be surprisingly rewarding considering the dullish civics lesson it might have become. In the year 1975-76 Muskie is squiring a revised Clean Air Act through his subcommittee hoping it will be a ""minimal"" bill that doesn't tamper excessively with the strict auto emission standards worked out by his own committee in 1970. The auto companies are howling and the bill will be modified: the question is how much. Asbell follows the wrangling, the obstruction and compromise with the help of the senator's numerous aides, themselves little potentates on the Hill. Muskie is also running for reelection in Maine, facing a possible primary opponent and finessing a possible presidential bid. As, bell monitors the senator and his staff as they maneuver through these perilous shoals--fascinated with the senator's ""team,"" the constant state of high pressure, their devotion to easing his way. He notes that among senators courtesies are excessive, genuine intimacies rare, ""lest it mitigate the freedom to fight."" Business--especially the preparation of a Bill--proceeds with agonizing languor. Asbell is enthralled by the process as a fine balancing of bold initiatives with vested interests. A more cynical observer might feel that Muskie's version of the Clean Air Act lost, tout court. The book itself is a kind of protracted ""Day in the Life of. . ,"" too long in terms of results, but for D.C. watchers a sure thing.