Political activist Scott Nunnery came to Ohio in January 2004 to help rally progressive voters behind John Kerry, the Democratic presidential candidate. Kerry, still a U.S. senator, has long since packed up his campaign. But Nunnery and the voter group that employs him stayed behind to create a permanent campaign. That's because Ohio remains a key battleground in national politics. With important congressional and statewide offices being decided in this year's elections, activists representing Democratic and Republican interests are already gearing up. "We are building a movement, and in a state like Ohio, it takes time," Nunnery, state director of...