A book of poetry focusing on race and social justice is the cornerstone of conversations Denver hopes to start among residents across the city. The citywide program, Denver Talks, will be distributing 1,200 free copies of poet Claudia Rankine’s “Citizen: An American Lyric.” The city will also be hosting a series of events, workshops and talks around the book that will culminate with two free talks with the author, led by Mayor Michael Hancock. “There are strong forces working to divide us,” Hancock said during a news conference to announce the series Wednesday.