BOOK REVIEW : The Politics of Race and Taxes in America : CHAIN REACTION: The Impact of Race, Rights, and Taxes on American Politics, <i> by Thomas Byrne Edsall with Mary D. Edsall</i> ; W.W. Norton, $22.95; 339 pages

The latest micro-trend in the American media is the discovery that politics in general--and the Democratic Party in particular--is hopelessly dysfunctional. And so say the authors of the newest title in the library of political despair, “Chain Reaction.”

“The national Democratic Party enters the fray tired, buckling at the knees after five defeats in six rounds; its defenses down, gasping for a second wind,” they write of the upcoming 1992 presidential campaign. “The Democratic Party as it is now constituted is in danger of losing its stature as a major competitor in national politics.”

But Thomas Byrne Edsall, a reporter for the Washington Post, and Mary D. Edsall, his collaborator (and spouse), have thought more deeply--and offer a far more thorough and considered analysis--than most of the other pundits and prophets of doom. And it’s refreshing to come across a book about politics that speaks in terms of the quality of life of men, women and children in the real world rather than merely the winning and losing of elections.

“Partisan competition is perhaps the most effective mechanism with which to force an assault on the problems of poverty, of the underclass, of the working poor,” the Edsalls write.

“The failure of the political system to function as a generative force is reflected in the deterioration of conditions--of economic security, family and employment--for those in the bottom third of the income distribution.”

The title is somewhat obscure--”Chain Reaction” has nothing to do with nuclear fission--but the authors make it plain that American politics have reached “a point of political combustion . . . as a linked series of highly charged issues collide.” The resulting explosion, they suggest, threatens to obliterate the status quo of American politics.

The Edsalls point to four key issues as the elements of the critical mass: race, civil rights, Democratic Party reform and the tax revolt. Of these issues, the Edsalls insist, race is by far the most volatile and the most pervasive. “The traditional ideological partisan divide,” they argue, “has been infused . . . with racial and race-coded meanings.”

“Chain Reaction” is, among other things, a comprehensive survey of a quarter-century of American politics, starting with the momentous debate over peace and freedom in the Johnson-Goldwater race of 1964 and concluding with the virtually meaningless media manipulations of the Bush campaign of 1988, which successfully exploited what the authors neatly sum up as “the furlough-pledge-ACLU-death penalty-and-flag themes.”

The Edsalls’ painstaking account of our recent political history traces an ascending curve of Republican electoral victory and a plummeting curve of Democratic failure, all as a result of the successful Republican strategy of characterizing the Democrats as the party of racial minorities and have-nots.

“Regardless of the legitimacy of the issues of black poverty and crime as subjects for public policy debate,” the Edsalls write, “their political function has been to polarize the electorate in a manner beneficial to the development of a majority conservative coalition.”

The authors insist that “Chain Reaction” is about “the political, not the moral consequences” of the sea of change in American politics, and it’s perfectly true that they have adopted a professorial tone that gives their book the tone of a civics text rather than a broadside. Indeed, it is a scholarly and, at times, even an elegant book, but it’s no easy read.

What distinguishes “Chain Reaction” from its competitors, however, is the sense of moral purpose that infuses the otherwise cool political analysis. They are willing to speak the “L” word out loud, and they honor liberalism for its historic commitment “to oppose racism, prejudice and oppression.”

And, above all, they are willing to call for “a sustained and vibrant insurgency” as an essential ingredient of not only American politics, but American civilization itself.

Next: Richard Eder reviews “Murther and Walking Spirits” by Robertson Davies (Viking) .