Sen. Hillary Clinton's (DNY) preliminary announcement that she will seek the nation's highest office is having a profound effect on America's pre-teen girls, thousands of whom are forming their own exploratory committees to gauge early reaction to possible presidential bids. 'I just think she's so great the way she's laying out her platform and putting out feelers,' said 9-year-old Jen Villeneuve of St. Louis, who recruited former John Kerry campaign staffers to come with her to Iowa this week to discuss her energy policy with top ethanol producers. 'I want to be just like her, especially in regards to her appeal to middle-class working families with pre-college children.' In a related item, sales of junior-sized pantsuits and sensible shoes have doubled nationwide. 