"Back to Blood," by Tom Wolfe Tom Wolfe's move from the New Journalism to fiction writing, undertaken a quarter-century ago, now seems on a par with Babe Ruth's shift from the pitcher's mound to the regular batting order. But from genre to genre, the fundamentals of Wolfe's game have stayed the same: a concentration on behavioral codes and status; the dominance of big themes over private emotions. Exuberance continues to rule his italicized, exclamatory and onomatopoetic pages. As the volume and vulgarity of American life have risen ever higher, Wolfe has pumped up the jam and just plain kept up. In "Back to Blood," the octogenarian novelist has characters sporting the "double-stubble" of deliberate unshavenness; defriending one another on Facebook; wearing rasta-rap T-shirts that say UZ MUVVUZ; and filming a reality show called "Masters of Disaster," on which ruined billionaires begin their public resurrection. To this self-proclaimed devotee of Balzac, milieu has always been all: New York investment banking in the 1980s ("The Bonfire of the Vanities"); Atlanta real estate in the "90s ("A Man in Full"); the hookup college campus of the early naughts ("I Am Charlotte Simmons"). Wolfe has now headed to Miami, not to retire but to watch the gaudy clash of that city's different ethnic and financial populations. Nestor Camacho, an overbuilt, well-meaning Cuban-American cop, is his main character, the figure who gets tangled up in all the novel's plotlines. Nestor achieves instant local fame when he climbs the 70-foot mast of a schooner in Biscayne Bay to rescue, and arrest, a small, shadowy man seeking asylum from Castro's regime. But the athletic bravery that makes him a hero on the pages of The Miami Herald turns Nestor into a pariah within his own Cuban-American enclave of Hialeah: "You arrest a guy 18 metros de libertad!" scolds his father. The predicament is interesting, but Wolfe doesn't fully develop its possibilities. Before long, he's got Nestor arresting a "6-foot-5, 275-pound accused drug dealer who was in the process of choking a brother officer to death" - and then getting suspended from the force when a YouTube video of the incident, containing his partner's nasty racial abuse of the suspect, puts Nestor in the middle of a power struggle between Miami's black police chief and the city's Cuban-­American mayor. As if this weren't enough woe, Wolfe also draws Nestor into an art-fraud investigation being conducted by John Smith, the Herald reporter who wrote up his Biscayne Bay heroics. Miami has just named a huge new museum for a Russian plutocrat, Sergei Korolyov, and it now seems that the modern paintings he's donated are forgeries. This art plot gives Wolfe an opportunity to stage some boisterously venal scenes, but a lot of its action might be happening in any big American city, not just the Miami he's otherwise so busy particularizing. Moreover, even with its contemporary dollop of Russian dressing, this portion of the novel feels a little tired: Wolfe has been banging the drum against modern art since "The Painted Word" appeared in 1975, back in his nonfiction days. He has admitted that an art-world story line had to be excised from a draft of the already overstuffed "Man in Full," and the one here in "Back to Blood" might have been cut loose too. Magdalena Otero, Nestor's estranged girlfriend, also has more than enough on her plate, even before Wolfe mixes her up with Sergei Korolyov. Eager to transcend the blinkered world of Hialeah, she's already gotten involved with her boss, Dr. Norman Lewis, a psychiatrist who puts wealthy clients seeking relief from porn addiction in thrall to himself instead. Magdalena's position as Norman's girlfriend and nurse forces her to wade into "the pustular oozing of complete freedom" and allows Wolfe to concoct some incidents as squalid as anything in the old Miami-set series "Nip/Tuck." But what remains most interesting about Magdalena is her hunger for assimilation and distinction - the great never-ending American status drama. Wolfe shows her listening to a roommate's urging that she put on a sluttier outfit for a big evening with Norman: "Look, Magdalena, what do you want to look like, some cubana wannabe americana wearing a proper dress from the tag sale at the discount mall?" Wolfe's title and theme may posit how "the bloodlines that course through our very bodies" are reasserting themselves and driving us toward an ever more volatile identity politics; but this new book really shows how much juice and complication remain in the great national drive to fit in and then rise. The greatest snob in the novel is a mixed-race, Haitian-born professor of French at Everglades Global University who is furious that he's being made to teach Creole. Professor Lantier overspends to furnish his Art Deco house; invests all his hopes in his light-skinned daughter; and is revolted by his son's desire to sound and look like one of his black classmates: "What a mess the two of them were!. . . jeans pulled down so low on their hips you couldn't help but see their loud boxer shorts . . . obviously the lower and louder, the better. The pants of both boys ended in puddles of denim on the floor. Thomas Mallon's most recent book is a novel, "Watergate."