Susan Sarandon takes over as host as the series opens its sixth season with "The Political Dr. Seuss," an affectionate profile of Theodor Seuss Geisel (1904-91) that focuses on the political and social messages in his children's books (Yertle the Turtle, for instance, was a stand-in for Hitler). But, says producer-narrator Ron LaMothe, "it was done with such finesse that few realized he was being political at all." Not always. Such books as "The Lorax" (about the environment) and "The Butter Battle Book" (on an arms race) are strident, and Geisel drew unsubtle political cartoons for the left-leaning New York City newspaper P.M. during World War II. Subtle or not, though, Geisel "believed in goodness and he believed in honesty," says biographer Judith Morgan. "And he believed in mischief."