LATIMES/The new realities of Mexico are replacing fond memories of the nostalgic past for many Mexican-Americans. A recent example is 33-year-old Bobby Salcedo. The El Monte, California school board member and his wife had returned to her hometown during Christmas to visit family and friends. A few days later, gunmen burst into the bar where they were drinking , kidnapped Salcedo and five other men. They were later found shot to death execution-style and dumped near a canal.