Mardi Gras, such as it is, is in full swing in the small section of New Orleans that still looks like it did last year at this time. Civic leaders are hoping the weeklong party will demonstrate the city’s resilience to the nation, but the truth is that no one ever really doubted that the bead-throwing floats and drunken revelers would return. “After Katrina, the lingering question is whether the New Orleans cultural traditions that had sprung up spontaneously in African-American neighborhoods would survive.”