Book excerpt: The Struggle Within is an accessible yet wide-ranging historical primer about how mass imprisonment has been a tool of repression deployed against diverse left-wing social movements over the last fifty years. Berger examines some of the most dynamic social movements across half a century: black liberation, Puerto Rican independence, Native American sovereignty, Chicano radicalism, white antiracist and working-class mobilizations, pacifist and antinuclear campaigns, and earth liberation and animal rights. Berger’s encyclopedic knowledge of American social movements provides a rich comparative history of numerous social movements that continue to shape contemporary politics. The book also offers a little-heard voice in contemporary critiques of mass incarceration. Rather than seeing the issue of America’s prison growth as stemming solely from the war on drugs, Berger locates mass incarceration within a slew of social movements that have provided steep challenges to state power.