In one of the more surprising moments of the Democratic presidential debate Sunday night, Bernie Sanders said he opposes the lawsuit that nine Sandy Hook Elementary School parents brought against Remington, the manufacturer of the AR-15 assault rifle that was used to murder their children in 2012.

"What people are saying is that if somebody who is crazy or a criminal or a horrible person goes around shooting people, the manufacturer of that gun should be held liable," the Vermont independent senator said. "If that is the case, your position is that there should not be any guns in America, period."

The shooting in Newtown, Connecticut, left 20 children and six teachers dead. The shooter unloaded 154 rounds of bullets from an AR-15, the commercially available, semi-automatic version of a weapon that was originally manufactured for use by the U.S. military. That rifle, built for warfare, can fire 30 rounds in under 10 seconds and is powerful enough to pierce body armor. The Bushmaster rifle Lanza used can reportedly fire 45 rounds per minute.

Nine families of students who were killed and one teacher brought a lawsuit against Remington and the distributors and sellers of the AR-15 in 2014, seeking to hold them accountable for marketing and selling the deadly weapon to the general public. The case will challenge a 2005 federal law, the Protection of Lawful Commerce in Arms Act, which gives gunmakers immunity from these kinds of lawsuits when their products are used in mass killings.

Former Secretary of State Hillary Clinton pointed out Sunday that, as a senator, she voted against the bill that gave gunmakers immunity and thought it was a "terrible mistake," while Sanders voted for it. She strongly disagreed with Sanders about the lawsuit against Remington and offered her passionate support for it.

"I want people in this audience to think about what it must feel like to send off your first-grader, a little backpack maybe on his or her back, and then the next thing you hear is that somebody has come to that school using an automatic weapon, an AR-15, and murdered those children," Clinton said. "Now they are trying to prevent that from happening to any other family, and the best way to do that is to go after the people ... you know, we talk about corporate greed, the gun manufacturers sell guns to make as much money as they can make."

Clinton added that the National Rifle Association lobbied for the immunity bill to be passed. "They basically went to the Congress, and they said, 'Give us absolute immunity,'" Clinton said. "No other industry in America has absolute immunity, and they cause harm all the time."

Sanders pointed out that he lost a statewide election for Congress because he was the only candidate who supported restricting the sale of military-style assault weapons -- but he stood by his position that suing gunmakers isn't the answer. "What you're really talking about is saying, 'Let's end gun manufacturing in America,'" he said.

Clarification: Language has been amended to indicate that the weapon Adam Lanza used in the Newtown shooting was not military-grade.