As Virginia Thomas tells it in her soft-spoken, Midwestern cadence, the story of her involvement in the "tea party" movement is the tale of an average citizen in action. "I am an ordinary citizen from Omaha, Neb., who just may have the chance to preserve liberty along with you and other people like you," she said at a recent panel discussion with tea party leaders in Washington. Thomas went on to count herself among those energized into action by President Obama's "hard-left agenda." --CLIP She is the wife of Supreme Court Justice Clarence Thomas, and she has launched a tea-party-linked group that could test the traditional notions of political impartiality for the court. In January, Virginia Thomas created Liberty Central Inc., a nonprofit lobbying group whose website will organize activism around a set of conservative "core principles," she said. The group plans to issue score cards for Congress members and be involved in the November election, although Thomas would not