Democratic U.S. Rep. Rick Nolan and GOP challenger Stewart Mills on Tuesday sparred over guns, Obamacare, tax reform and even engaged in a little class warfare in their one and only debate from Minnesota's hottest political race.

Nolan, who also served in the House of Representatives in the 1970s, faces a challenge in Mills, the energetic 42-year-old scion of Mills Fleet Farm. Ray "Skip" Sandman, a Green Party candidate, also participated in the debate.

In the 90-minute forum at a theater in Duluth, the candidates sat down coffee-table style. Mills tried to tar Nolan as a gun-loathing liberal whose values don't match up with the political blends in Minnesota's Eighth Congressional District. Nolan took repeated swipes at Mills' net worth, which is between $47 million and $153 million, according to personal financial disclosures.

"If we want to rebuild this middle class, we need to get away from this trickle-down theory," Nolan said, when asked about tax reform. "Stewart, you made more money … sitting here in an hour and a half … than the minimum-wage earner will make in a week. … The rich are getting richer and the poor are getting poorer."

Mills defended his company and family, saying they work hard and play hard and building the business meant their hands got dirty and even "a little bit bloody sometimes." Mills said he favored flattening the tax code to be friendlier to Main Street.

Throughout the feisty and provocative debate, Mills referred to Nolan as "Representative Nolan" while Nolan called the third-party candidate "Mr. Sandman" and Mills "Stew" or "Stewart." Nolan jumped in front of Mills at a couple of points and once completely cut him off in the middle of his time — something Mills called "rude" before asking for his time back.

When asked to answer a question, Sandman, who on some issues agreed with Mills and others agreed with Nolan, said he was simply enjoying listening to Mills and Nolan face off.

On guns, Mills touted his "A" rating by the National Rifle Association and said Nolan's positions on restricting semi-automatic weapons and limiting magazine capacities were not in line with the district's values.

"We need to enforce the laws we currently have rather than making up new ones," Mills said.

Said Nolan to Mills: "I don't need a semi-automatic rifle to shoot a duck. Maybe you do. Maybe you should spend more time on your shooting range."

Neck-in-neck race

Most polls show Mills and Nolan running within a couple of percentage points of each other. Once a DFL stronghold, the Eighth has become a swing district. Voters there dumped a 17-term Democrat in the 2010 Tea Party sweep for GOP Rep. Chip Cravaack. He served a single term before voters bounced him in favor of Democrat Nolan, who had been running a sawmill and pallet manufacturing company.

Mills, a relatively young and hip, long-haired businessman, has fashioned himself as a small-government Republican. Though he touts more libertarian ideas than socially conservative ones, Mills did garner an endorsement Tuesday from the Tea Party Express.

Cash advantage

Nolan has consistently had more cash on hand than Mills this year, even with Mills' personal contributions of more than $167,000 to his campaign through July.

Nolan's camp said Tuesday the incumbent brought in $641,000 in the third quarter — his best haul to date. Mills' campaign declined to say how much the candidate raised in the third quarter Tuesday. Reports are due to be filed in the next week.

Split on mining, energy

Mills said he supported both the construction of the Keystone oil sands pipeline and the Sandpiper line, which will deliver crude from North Dakota to an existing terminal in Wisconsin. He called Nolan inconsistent in his support for mining and energy.

"We're not quite sure where Rep. Nolan is," Mills said. "He can say he's for it right now, but where's he going to be tomorrow?"

Nolan said he also favored both projects, as long as they followed environmental rules. Nolan said he grew up at a time when "condoms" and "turds" polluted rivers and acid rain was wreaking havoc on forests.

"We must be compliant with good, sound, environmental rules and regulations and we have the technology to move forward with mining," Nolan said. "We need to protect our environment as well."

Nolan also emphatically pushed an isolationist message on dealing with the Islamic extremists in Iraq and Syria, saying the money the United States is spending in the Middle East will only create more problems.

"No matter how well-intentioned we are, we have given money and arms to everyone on every side of this fight," Nolan said. "We can ill afford it. America will not be around in 30 years," he said, if the country doesn't invest in its own people and infrastructure.

Mills struck a moderate tone, saying the United States should furnish training, arms and logistical support overseas to protect American interests.

Reform Obamacare?

On the Affordable Care Act, Mills said he favored health care reform that protects people with pre-existing conditions but he supports reforming the law to allow people to buy and sell plans across state lines.

Nolan, who favors a single-payer system, snapped.

"Now Mills is saying he supports many of the things in the ACA and then he is saying he wants to repeal it. Talk about doublespeak," Nolan said. "It's starting to smell like a barn on a warm Sunday afternoon."

Allison Sherry • 1-202-383-6120