A feminist, an outspoken activist, a woman without a college education, Midge Costanza was one of the unlikeliest of White House insiders. Yet in 1977 she became the first female Assistant to the President for Public Liaison under Jimmy Carter, emerging as a prominent focal point of the American culture wars. Tasked with bringing the views of special interest groups to the president, Costanza championed progressive causes even as Americans grew increasingly divided on the very issues for which she fought.

In A Feminist in the White House, Doreen Mattingly draws on Costanza's...