Hacker has written works on social policy, health care reform, and economic insecurity in the United States.

He was widely recognized as a contributor to the health care plans for three of the leading Democratic candidates — Barack Obama, Hillary Clinton, and John Edwards — in the presidential election of 2008.

Hacker's 2010 book, the New York Times bestseller Winner-Take-All Politics: How Washington Made the Richer Richer--and Turned Its Back on the Middle Class (Simon & Schuster), written with Paul Pierson of UC Berkeley, argues that since the late 1970s the American middle and working classes have fallen further and further behind economically because policy changes in government favor the rich and super-rich.

Their 2016 book American Amnesia: How the War on Government Led Us to Forget What Made America Prosper argues for the restoration and reinvigoration of the United States mixed economy.

Hacker is married to Oona A. Hathaway, a Professor of Law at Yale University and former Supreme Court clerk to Sandra Day O'Connor.