POLITICAL SCIENTIST Ethel Klein's first book goes a long way towards proving several commonly held beliefs about women's political behavior. Her comparisons of the presidential elections since the Nixon/McGovern race show a sometimes small but statistically significant difference in the way women and men choose candidates and parties and rank issues. Gender Politics, however, may be more important for the future of the Women's Movement for what it says about the relationship between group consciousness and mass political action.

Klein argues--in an academic thesis-evidence-thesis-impact style which occasionally tries the reader's patience--that women's changing roles have led to a transformation of their consciousness. This change in turn has provoked a recognition that they, as a group, are the victims of discrimination. Present day feminist politics has its origins in this discontent.

For the Women's Movement to become an effective protest movement--one which would lead to legislative changes--its leaders had to attract wide-ranging public support from men as well as women. With due praise for the role of male feminists in the struggle for equal rights. Klein distinguishes between men's and women's commitment to feminist ideals. Although men may say they support big-F Feminism, they do so more out of a belief in traditional liberal doctrine than a recognition that discrimination has held women back.

To support her claims, the Columbia political science professor takes advantage of a wealth of census data showing the movement of women into the labor force and higher education, revolutions in contraception and increased life expectancy since the turn of the century. She uses a Center for Population Studies survey of the American electorate following the presidential elections from 1972 to 1980 to prove the emergence of a women's vote.

KLEIN has made an obvious effort to legitimize the feminist politics genre in the minds of mainstream political scientists. To a literature which has consisted mostly of fiction and pop social science works on women's political behavior--ranging from Bella Abzug's faulty prediction of how women would bring Reagan defeat in November to Gloria Steinem's telling collection of essays describing her personal encounters with sexism, discrimination and feminism--the former Harvard professor adds a quantitative and historically supported thesis about the genesis of feminist politics. She has produced perhaps the first unabashedly academic treatise on the often talked about but little understood Women's Movement.

These well-intentioned attempts to legitimize the topic, however, have carried a price. The statistical evidence she uses to support popular feminist views of a women's vote may bring the study of women's political behavior into the circle of legitimate research topics, but it makes for convoluted writing at times.

Both the casual and committed reader would be well served to skim the first half of the book which traces changes in women's lives, emphasizing shifts in the economic and public spheres, and how they have led to a feminist consciousness.

But by all means, read the rest Klein's work may not be as zippy or as timely as a New York Times post mortem on Gerry Ferraro, but it's impact on the Women's Movement will probably be more significant.