It is no wonder that Marilyn Hacker's Presentation Piece was greeted with such éclat—and swept several prizes—a half dozen years ago. At a time when so many of her more touted peers had settled for the studied simplicities of workshop murk, she knew how much more difficult it is to be precise than profound. And her precision was manifest, first, in her prosody. She had a prodigious talent for verse, and lavished it with gusto and flair: the straw of experience was woven, as if overnight, into the pure gold of canzone and sonnet, sestina and villanelle … even free verse. But she was no mere littérateuse. Like Dorothy Parker, who once said that she followed the exquisite footsteps of Miss Millay in a pair of old sneakers, Hacker laced her prosodic skill with salty topics, a novelist's eye for wry or sour details, and a...