Gilbert, who joined the Hamilton faculty in 1976, earned a Ph.D. in sociology from Cornell University. His primary research interests are Latin American society and history and the American class system. Gilbert is the author of The American Class Structure in an Age of Growing Inequality (Sage, 2011), Mexico's Middle Class in the Neoliberal Era (University of Arizona Press, 2007), Sandinistas: the Party and the Revolution (Blackwell, 1988), and La Oligarquía Peruana: Historia de Tres familias (Horizonte, 1982). In 1990, he was research director to the successful congressional campaign of Bernard Sanders (Independent-VT) and later served as legislative assistant in Sanders' congressional office. In collaboration with the polling firm Zogby International, Gilbert and his Hamilton students have conducted a series of widely reported national surveys, most examining the views of high school students, on such topics as gun control, gay rights, abortion, Muslims in America, and patriotism.