Vermont liberal Sen. Bernie Sanders said Sunday that the majority of gun owners are responsible and obey the law.

Appearing on CNN's "State of the Union" Sunday, Sanders said that a gun manufacturer should be no more responsible for a murder performed by their product than a hammer manufacturer is responsible "if someone beat someone over the head with a hammer."

Sanders was taking on detractors who have pointed to a bill he voted for that shields firearms manufacturers from being sued by gun violence victims. Presidential rival Hillary Clinton made reference to this bill in New Hampshire Saturday, saying that it was the "height of irresponsibility not to talk about it."

Sanders noted Sunday that he has a pretty poor grade of a D- from the National Rifle Association and has voted for the assault weapons ban.

Sanders suggested that he could broker a "serious debate and action on guns," but that it won't happen if "we have extreme positions on both sides."

"I come form a state that has virtually no gun control but the people of my state understand that guns in Vermont aren't the same thing as guns in Chicago," he said.

The senator has been drawing big crowds in Iowa and other places, but still lags behind former Secretary of State Hillary Clinton in the polls.