Jody Cooley is a little nervous.He admits as much Friday as his wife, Lora, rushes around a pavilion in Gainesville’s Longwood Park, tying balloons, adjusting a microphone, positioning signs — putting the final touches on what will, in minutes, be the official start to a challenge Democrats in Northeast Georgia have not mounted since 2008.Cooley is running for Congress.Days after a contentious runoff election for the Republican nomination, the choice for Northeast Georgians in the 20-county 9th District U.S. House seat is now between Cooley, a Democrat, and Republican Doug Collins.Both men are attorneys from Gainesville.But Collins is well-funded, has political experience and represents a party that has dominated the district in recent elections. He also has been campaigning throughout the region for nearly a year. Already, more than 39,000 of the district’s voters have showed their support for Collins in the party primary, and he has the support of Georgia Gov.