Leadership in America: a hopeful view; Changing of the Guard, by David S. Broder. New York: Simon & Schuster. $14.95.

David Broder has written a hard-cover counterweight to the political campaign from which the United States is just emerging. A counterweight of cautious optimism about America's future -- an optimism rooted in the significant abilities of the next generation of political leaders.

For too many Americans this has been a presidential campaign of shoulder-shrugging and cynicism, of unhappiness with all candidates.And of wondering uneasily about the future -- about the ideals, the demonstrated abilities, the qualities of thought of tomorrow's potential leaders.

Broder's book will buoy the mood of many with such concerns. This highly respected political columnist of the Washington Post has brought incisiveness and exceptional research to his examination of a kind of hiatus in our political history: an interregnum between the generation of leaders moulded by the Great Depression and World War II, and tomorrow's chieftains, whose outlooks were shaped by the civil rights and Vietnam eras.

The book has three sections. The first examines those who rose to influence during the Kennedy, Johnson, Nixon, Ford, and Carter years. The second considers the key "networks," or informal groupings, of tomorrow's leaders -- the new right, blacks, labor and business, and so on. The third looks into the tomorrow nearly here -- the shifts of power to the West, the South, and the suburbs; and the pervasive political effects of King Television.

Throughout, Broder brings us, in nugget form, the ideas and ideals of scores of secondtier leaders now poised to spring to positions of top authority. Men and women like Vilma Martinez, unable to speak English when she began first grade and now a Columbia Law School graduate and a prominent feminist and Hispanic leader. Like Robert K. Dornan, a one-time Los Angeles TV talk-show host who is now a Republican Representative from California. And like Douglas Bennet, administrator of the federal Agency for International Development with a PhD in history.

"There is a lot of talent coming along," Broder says. "We are reaping a rich reward as a nation for the investment we have made in the past two decades in our education system."

It's a conclusion the reader is likely to share. And along the way, while meeting these talented people, one gets their ideas in perspective; despite Broder's modest assertion that he is "a strictly amateur historian," he fills in many knowledge gaps. Whizzing past in capsule summary is everything from the history of women's suffrage to a recap of the business-government relationship.

It all points the reader toward tomorrow, a tomorrow frought with challenges, says Broder. Not only the unknown challenge of events, or the known but immense challenge of reforming government so that it works well, and efficiently. But also the challenge from within confronting tomorrow's leaders: Can those who once organized protests against government action now organize government itself?

In all, this is a book for anyone seriously interested in the present and future functioning of government.