The Tyranny of the Majority  (1995)
by Lani Guinier

Excerpted from the book cover:

Lani Guinier is Professor of Law at Harvard Law School. She lectures on issues of civil rights, social justice, and democracy, and is the author of Lift Every Voice: Turning a Civil Rights Setback into a New Vision of Social Justice and coauthor of Becoming Gentlemen: Women, Law Schools and Institutional Change.