(AP) — Georgia Democrat Michelle Nunn has spent the past month hammering away at Republican David Perdue's career as a business executive, making a dispute over his role in outsourcing jobs the hallmark of her campaign for U.S. Senate. [...] backed with fresh cash from national Democrats, Nunn could yet complicate the GOP's path by squeezing out a victory — or at least force a runoff that would leave the midterm congressional elections unsettled until January. Nunn was at it again Wednesday, highlighting Republican opposition to a minimum wage hike while portraying Perdue as an overpaid CEO who mistreated employees. Collins and other Republicans predict Perdue nonetheless will benefit from the historical trend of midterm elections producing electorates that are smaller, older, whiter and more conservative than in presidential election years. New voter registration figures released this week show the overall electorate in Georgia is slightly smaller than in 2012, with whites now making up 58 percent of the state's roughly 6 million voters. Democrats argue that adds to the power of minority voters who make up Nunn's core base of support, while her attacks on Perdue's business record allow her to reach white moderates and independents who didn't vote for Obama.