...Once, tough-guy columnists like Chicago's Mike Royko, New York's Jimmy Breslin and Boston's Mike Barnicle ruled the roost from the local bar, hanging with cops, barbecuing politicians and spinning tales of urban angst. But few local columnists these days have captured that compelling voice, and the reason has much to do with the way the world, and the newspaper racket, have changed.... Across the country, many metro columnists are polite or parochial or tend toward soft-feature blandness. Some newspapers seem to dole out the slots on demographic grounds -- fielding a white man, a woman and a minority -- who...