Few races on today’s primary ballots are as competitive as the three-candidate Republican race in South Dakota’s at-large district. But none may be more civil.

South Dakota Secretary of State Chris Nelson and state Reps. Kristi Noem and Blake Curd are keeping it clean, eschewing personal and political attacks in favor of emphasizing their personal and professional backgrounds and very similar conservative views on fiscal and cultural issues.

One reason the campaign is positive, say the candidates and party officials, is that the contenders respect one another and don’t want internecine squabbling to complicate what they see as a golden opportunity to unseat Democratic Rep. Stephanie Herseth Sandlin, who is serving her fourth term in a state that leans Republican.

Much of the GOP electorate still remembers a fractious gubernatorial primary in 2002, when Mike Rounds, then a little-known state Senator, ran a positive campaign and scored an impressive come-from-behind landslide win over Attorney General Mark Barnett and former Lt. Gov. Steve Kirby, who frequently attacked one another and soured their image with voters.

“Among Republican voters, that primary really turned a lot of people off, and time and time again we’ve had Republicans admonish all three of us, ‘Don’t go there. Don’t do that. We don’t want to see that,'” Nelson said. “And so we understand that. That’s in the back of our minds, that Republican voters don’t want to see that.”

Whoever is nominated today, GOP officials say, will be a much stronger challenger in the fall than the weak GOP candidates who were trounced by Herseth Sandlin in the pro-Democratic 2006 and 2008 election cycles.

“We’ve got three outstanding leaders who all could definitely beat Stephanie Herseth Sandlin,” said Drake Olson, the chairman of the Republican Party in vote-rich Minnehaha County, which includes Sioux Falls. “We’ve got such great options in the Republican Party as a whole across South Dakota.”

Republican officials say they’d be happy with any of the three candidates, all of whom are running only slightly behind Herseth Sandlin in early polling. South Dakota law requires a winner to clear 35 percent of the vote to avoid a runoff, a near-mathematical certainty in a three-candidate race. Some Republican officials think Noem has the momentum, but a large number of undecided voters makes the race hard to handicap.

“I really believe there are a lot of undecideds still in that race,” said Olson, who is neutral. He said that many voters are undecided among Curd, Nelson and Noem “because they are all just phenomenal candidates.”

Curd has dominated the field in fundraising, having raised $475,000 through May 19, and he put in $42,000 of personal money on May 24 and $56,000 on May 28.

Noem entered the race only in February, four months after her opponents, though she’s had success raising money of late, and her $244,000 in receipts puts her ahead of Nelson. He’s raised the least amount of money, but he has the highest name recognition, having been elected statewide twice.

With little to distinguish themselves on policy, the candidates are talking about their backgrounds.

Noem, a two-term legislator from a rural district in the east, has talked about her farming and ranching background and running several small businesses.

“The main thing that South Dakotans are looking for is someone who understands what it’s like to have to run a business and live with a budget and make a payroll and have people depend on you to make good decisions,” Noem said. “That’s generally what we’ve been talking about — getting people back to work and jobs and trying to limit the government’s regulation that influences our economy here.”

As a freshman state legislator, Curd has the least formal political experience of the three candidates, something he’s emphasizing as a selling point in a race against two more seasoned politicians. He’s frequently noted his military service as an Air Force veteran and his medical background as a hand surgeon. Curd also was a visible opponent in South Dakota to the Democratic-led national health care overhaul.

“He’s not a career politician — he’s a doctor, a veteran, a father and a husband,” Curd campaign spokesman Joshua Shields said. “I think he would bring a different approach to being South Dakota’s Representative than definitely our current Representative and some of the others in the primary field as well.”

Nelson said that he’s taken on some tough issues as secretary of state and handled them fairly. He also said he has a farming and ranching background and promises to hold open town hall meetings at least once a month.

The candidates also have focused on electability. A Rasmussen Reports poll taken May 27 showed Noem behind Herseth Sandlin by 3 points, Nelson trailing by 4 points and Curd behind the Congresswoman by 7 points.

Nelson said the margins in that poll are virtually indistinguishable and noted he has a head start with the electorate.

“I’ve won two statewide elections, and that’s one of the things that’s a little unique about South Dakota’s Congressional district — the fact that it does cover the whole state,” Nelson said. “I’ve won two statewide elections with all the counties in the state, whereas my two opponents have won either one or two legislative elections in a much smaller area.”