A day after publishing a cartoon that drew fire from critics who said it evoked historically racist images, the New York Post apologized in a statement on its Web site — even as it defended its action and blasted some detractors. Many of those critical of the cartoon said it appeared to compare President Barack Obama to a chimpanzee in a commentary on his recently approved economic stimulus package. “Wednesday’s Page Six cartoon — caricaturing Monday’s police shooting of a chimpanzee in Connecticut — has created considerable controversy,” the paper said about the drawing, which shows two police officers standing over the body of a chimpanzee they just shot