Democratic presidential candidates Pete Buttigieg and Beto O'Rourke clashed over the issue of gun buybacks during Tuesday night's Democratic debate.

The South Bend mayor has repeatedly criticized O'Rourke for his support for mandatory gun buybacks, and he continued to hammer the former Texas congressman at the debate, arguing that O'Rourke's proposal undermines more plausible gun control laws.

"The problem isn't the polls. The problem is the policy and I don't need lessons from you on courage, political or personal," Buttigieg said. "Everyone on this stage is determined to get something done. Everyone on this stage recognizes or at least I thought we did that the problem is not other Democrats who don't agree with your particular idea of how to handle this. The problem is the National Rifle Association and their enablers in Congress and we should be united in taking the fight to them."

In response, O'Rourke, who has turned his flailing campaign into a single-issue vessel for promoting gun buybacks, said that the country owes survivors of gun violence a solution.

"We are at the cusp of building a new American majority to actually do things that congressmen and senators have been talking about with almost no impact for my entire adult life," he said.

As O'Rourke campaign has faltered, however, his decision to narrow his focus on gun control has done little to revive it. He stands at 2.6 percent in the RealClearPolitics average of national polls.