MONROE — Walton County is still getting to know U.S. Rep. Paul Broun, which might explain why his surname was spelled “Brown” on fliers for a town hall meeting last week in the county courthouse.

The Athens Republican has what he described as a second full-time job learning about his significantly redrawn district, which he hopes will send him to a third full term in Congress. Though Republicans ran the redistricting process, Broun saw his voting base shift enough that he has drawn at least one primary opponent.

Georgia added a congressional district because of the state’s population growth in the 2010 census, meaning all 13 of the state’s members of Congress have unfamiliar borders.

Broun’s district was caught between the new district, based in Gov. Nathan Deal’s home of Hall County, and that of Democrat John Barrow, who was forced to move from Savannah to Augusta to remain in a district that now has a strong Republican lean. The result was to move Broun’s district south and west, into territory that includes Atlanta’s outer suburbs and eliminates much of rural, archconservative northeast Georgia. Deal spokesman Brian Robinson said the big shift for Broun was necessitated by the rapid growth in North Georgia.

“Paul Broun is an ally of the governor, someone whose interest we would like to look after,” Robinson said. “We wanted him to have a good district to run in. It’s a Republican district that we think is a good fit for him. ... We know his new territory creates a lot of work in the next election cycle, but we feel confident that he’s going to get through that with flying colors.”

The district remains solidly Republican, but a primary challenge — even from a political novice such as former Army Lt. Col. Stephen K. Simpson — could become difficult.

“You never make money in the long run by betting against the incumbent, but he’s got a large chunk of his district that’s in effect an open seat — they don’t know him,” University of Georgia political science professor Charles Bullock said.

Broun, whose name is pronounced “Brown,” said two-thirds of the new district is outside his current boundaries, and he is meeting with any group that will see him. Tuesday night he was welcomed by Walton County’s current representative, Republican Rob Woodall of Lawrenceville, whose overpopulated district is shrinking down to most of Gwinnett and Forsyth counties.

Woodall and Broun teamed up for an hourlong town hall meeting, taking questions on issues such as tax policy, immigration and health care. Speaking to a couple of dozen voters, Woodall sounded like the wonky former congressional staffer that he is, describing the nuances of the appropriations process. Broun sounded like a candidate, pledging to eliminate the Environmental Protection Agency and make English the nation’s official language.

At the end, Broun asked for votes in the July 31 primary and proclaimed that this year for Walton County, “It’s going to be almost like having two congressmen. We’re both going to be working on your issues.”

After the meeting, Broun said he has spent considerable time cruising through his 15 new counties, including pieces of metro Atlanta’s Gwinnett and Henry counties. Broun said he met with the Atlanta Regional Commission as well as the chambers of commerce in Cobb and Fulton counties to better understand the economic issues facing Atlanta — particularly transportation needs.

Broun isn’t exactly seeking federal pork. In fact, he is a consistent nay vote on spending proposals and a rigid constitutionalist. He frequently introduces bills designed more to make a statement than a law. For example, during the debate over how to raise the nation’s borrowing limit to avoid a default, Broun introduced a bill to lower the debt ceiling.

His Republican primary, therefore, is atypical in that Simpson is challenging Broun from the middle rather than the right. During an interview Simpson called Broun an “extremist” and said he has made the 10th District a “laughingstock.”

Simpson, a banker and former congressional liaison from the Pentagon, said he would foster more bipartisanship. It’s a tricky argument in a GOP primary, usually a race to see who can be more conservative.

Bullock said the attack is out of necessity. “You’re not going to outconservative Paul Broun, so you’re going to come up with a different message,” he said.

Simpson also pressed recent ethical allegations against Broun. The watchdog group Citizens for Responsibility and Ethics in Washington, a nonprofit that traces its origins to Democrats, filed an ethics complaint against Broun last week for not disclosing the circumstances of $300,000 worth of loans he gave to his campaign during his first race in 2007.

Broun paid himself $28,000 in interest for the loans, which CREW raised as evidence of self-dealing. Broun spokeswoman Meredith Griffanti said the congressman took out a loan to help fund the campaign, and the reimbursement was for interest Broun paid to the bank. Under campaign finance law, Broun should have disclosed the origin of the loan in 2007, an oversight Griffanti attributed to inexperienced staff. She said it would be corrected in amended campaign finance reports.

During the interview, Broun dismissed Simpson as someone from outside the district — his home is in Macon, though he is originally from Milledgeville, which is in the district — moving in to challenge him out of long-held political ambition. Former U.S. Rep. Mac Collins has indicated that he is considering a primary challenge to Broun as well.

Broun likely will carry a significant financial advantage into the race. He reported $275,000 in his campaign bank account at the end of March. Simpson estimated that he had about $10,000 on hand.

Broun also has a key ally in Deal. Broun was an early supporter of Deal’s gubernatorial bid. In turn, Deal plans to campaign with Broun and help him raise money, Robinson said.

Broun has had only token opposition since winning a special election in 2007 to take over for the late Charlie Norwood. Bullock said this primary is crucial to determine whether Broun is able to stake lasting claim to his new terrain.

“Even if he survives this time but shows some vulnerability, then the buzzards will start to circle, then he’ll have another serious challenge in two years,” Bullock said. “If he sails to victory, he gets a pass for the rest of the decade.”