WILMINGTON — Four days before the primary election, Democratic candidates for the U.S. House of Representatives received one final chance to make their pitches to voters in a large forum.

In a debate broadcast on television and the radio Friday, hopefuls for the state’s open seat in Congress weighed in on guns, taxes and, in a humorous nod to a truck that spilled more than 20 tons of pennies in New Castle County Thursday, the cent.

Hosted by WDEL and WHYY at Widener University Delaware Law School, the event featured five of the six Democrats seeking the office. While there was general agreement on most issues, the candidates  differed in some regards.

Unlike the others, Scott Walker opposes a minimum wage increase, something he reiterated Friday. He also said he believes the United States should exit the Middle East, a stance not taken by the other four participants.

Mr. Walker said the United States should concentrate on violence within its borders, while others said the nation owes it to the world to help bring peace to the area.

At several points, 2014 state treasurer nominee Sean Barney called for the nation to rely less on military force and more on diplomacy.

2002 House nominee Mike Miller said the nation plays an important role as a global peacekeeper and should be involved in fighting the Islamic State terrorist group.

“I believe that the world looks to the United States to be a superpower and be what we are,” Mr. Miller said. “They look for us to help resolve issues and problems.

“And I’m fine with that, but ... I don’t want to see us in the Middle East, I don’t want to see us have boots on the ground in Syria, I believe that airstrikes will continue to work and I do believe that we need to come together with other organizations to fight ISIS. It’s not just an American problem, it’s a world problem.”

Each of the candidates sought to outdo one another on guns, pledging to support greater limitations and opposition to the National Rifle Association. Gun violence, state Sen. Bryan Townsend said, has become an “epidemic.”

Mr. Walker went farthest, calling for a ban on selling firearms.

“I’m the only candidate that’s had the nerve to propose a total gun ban nationwide. I’ve gotten a lot of flak for it, but right now, we need to start talking about a gun ban,” he said. “Why do we need all these guns?”

While Congress has blocked recent gun control laws, with votes falling along party lines, former state Labor Secretary Lisa Blunt Rochester said she would try to work with Republicans who are likely to be in the majority in the House after the November election to pass gun control. People can work together, she said, citing abortion legislation approved in Delaware with support from both parties.

“How many kids need to die, how many families need to go on Capitol Hill?” she said. “When you really think about this, it is about the relationships and the lack thereof that people have in Congress right now. They don’t see each other as human beings.”

Mr. Miller called for closing what some Democrats have referred to as the “gun show loophole,” which allows private firearm sellers to turn guns over to buyers without a background check.

Asked about the Affordable Care Act, aka ObamaCare, several candidates said they believe greater competition is needed between insurance companies to create lower prices for consumers.

“It’s an outrage the Republicans are not willing to look at the act without repealing it,” Mr. Barney said.

On the subject of growing the state’s economy, the candidates agreed the state can provide more support to small businesses and the workforce.

“Economic development can’t just be about these grants. It’s got to be a culture of innovation, of entrepreneurship but also based on strong public schools and strong public safety,” Sen. Townsend said.

In his closing statements, Mr. Miller echoed comments he had made at previous debates. In the only instance of direct criticism at Friday’s event, he questioned Mr. Barney, Sen. Townsend and Ms. Blunt Rochester, seeking to cast doubt as to their sincerity or judgment.

Elias Weir did not attend Friday. According to the moderator, he did not respond to an invitation.