The Libertarian Party will nominate a presidential candidate in Atlanta next month with all the hoopla of a national convention. But no one — including the party faithful — holds any illusion that a third-party candidate can win against President Bush or Democrat John Kerry. Instead, the presidential run is about getting the Libertarian message out and building interest in the party, which advocates limited government. "The No. 1 goal is to change public policy by electing candidates, and it's much more likely we'd elect a local candidate," said David Lockhart of Forest Park, the Georgia party's political director. "The...