What madine said. In each state, the winner must get, at a minimum, a plurality of votes (if less than 50%, the largest number). If Bush gets 45%, for instance, and Badnarik gets 3%, and Kerry gets 46%, Kerry wins the state. If this happens enough times, then a candidate that doesn't represent the preferred views of the American public may win. This has happened twice in the last twelve years; in 1992, when Ross Perot siphoned off enough votes from George H.W. Bush for Clinton to win, and in 2000, when Ralph Nader siphoned off enough votes from Al Gore for George W. Bush to win.
The fact is, it's not about Badnarik's 3%. What most people don't realize is, he's polling at that despite the vast majority of Americans not being exposed to his message. Don't get me wrong, I don't think he could pull off a win in this year's election, but the idea of the LP platform being presented to the American public clearly and cohesively, in a manner that sets the stage for future candidates, is the goal of having Badnarik recognized. Both he and David Cobb of the Green Party have reached the ballot in 49 or 50 states -- which means either are technically, electable; as such, I feel that their voices deserve to be heard.