Hillary Clinton seized her first opportunity to rip Bernie Sanders

Hillary Clinton slammed Sen. Bernie Sanders (I-Vermont) over gun control early in the first Democratic debate Tuesday night.

When asked by CNN moderator Anderson Cooper if Sanders went far enough to enact gun control measures, Clinton immediately shot it down.

"No, not at all. I think that we have to look at the fact that we lose 90 people a day to gun violence," Clinton said.

"It's time that the entire country stood up to the NRA," Clinton said, referring to the National Rifle Association, as the audience cheered.

Clinton also ripped Sanders' opposition to several key gun-control measures, including the "Brady bill."

"Sen. Sanders did vote five times against the Brady bill. Since it was passed, more than two million prohibited purchases have been prevented. He also did vote, as he said, for this immunity provision. I voted against it. I was in the Senate at the same time. It wasn't complicated to me. It was pretty straightforward to me that he was going to give immunity to the only industry in America - everybody else has to be accountable but not the gun manufacturers. And we need to stand up and say, 'Enough of that,'" she said.

Sanders began his response by highlighting his support for various gun-control measures, including an assault weapons ban and so-called "instant" background checks.

"Let's begin Anderson, that Bernie Sanders has a D Minus from the NRA," Sanders said.

But Sanders refused to say that he would allow victims of gun violence to sue gun shop owners over mass shootings, an issue that has become a source of controversy for him on the campaign trail.

"Do I think that a gun shop in the state of Vermont, which sells legally, a gun to someone, and that somebody goes out and kills someone, that that gun shop owner should be responsible? I do not," he said.