Debuting as an adorable, all-American-looking pop singer with a powerful vocal range and squeaky clean image, Jessica Simpson initially stood in the shadows of her equally young, equally blonde pop predecessors Britney Spears and Christina Aguilera in her early career. Routinely compared to the two divas—sometimes unfairly—Simpson has struggled to be nothing more than herself. Yearning to make her mark, Simpson found her true voice not in music, but on television. As the star of “Newlyweds: Nick & Jessica” (MTV 2003- ), a reality show co-starring husband Nick Lachey, formerly of the