Professor and media critic Eric Alterman shouldn't have much trouble explaining the title of his latest tract to a sympathetic Berkeley audience. Why We're Liberals: A Political Handbook for Post-Bush America puzzles over politicians' disavowal of the "L" word. While polls regularly show liberal positions holding sway on a number of key social issues, the word still seems to carry negative connotations even after eight years of Bush follies. A regular columnist for the Nation, Alterman has the right credentials to lead a thoughtful discussion on American progressivism and its discontents — a subject more relevant than ever in this extended primary season.