Clinton and Sanders Trading Blows on Gun Control Hillary Clinton's campaign is hitting Bernie Sanders for his gun control record.

 -- The gloves have come off.

Bernie Sanders and Hillary Clinton have begun trading jabs over the hot-button issue of gun control, which was the focus of a town hall hosted by President Obama and a renewed debate on both sides of the aisle.

Following a week in which the president outlined his planned gun control actions, Hillary Clinton is hitting her rival, Sen. Bernie Sanders, on his record -- and Sanders and his campaign are responding in full force, portraying the former Secretary of State as a flip-flopper.

“When it really mattered, Senator Sanders voted with the gun lobby and I voted against the gun lobby,” Clinton told Chris Matthews on “Hardball” tonight.

Clinton was referring to the “Protection of Lawful Commerce in Arms Act," legislation the Senate passed in 2005 that shielded firearms manufacturers and dealers from liability lawsuits. In 2005, Sanders voted for the legislation, while then-senators Clinton and Obama voted against it.

Clinton also noted that Sanders has voted against the Brady Bill, which mandates background checks for gun purchases, five times, and voted for the "Charleston loophole," an amendment to the Brady bill that makes it easier to buy a gun without a completed background check.

“This is a significant difference,” Clinton told Matthews, “and it's important that, you know, maybe it's time for Senator Sanders to stand up and say I got this one wrong. But he hasn't. He's defended his vote time and again."

Sanders has defended his votes, but said that he is willing to reconsider manufacturers being held responsible.

Sanders' campaign responded by resurfacing a 2008 mailer, showing Clinton attacked President Obama for cracking down on guns.

"Maybe Secretary Clinton should apologize for attacking the president in 2008 because he was too strong on gun control,” Sanders campaign manager Jeff Weaver said in a statement.

And Sanders Communications Director Michael Briggs said Clinton's team has gotten "nervous and nasty."

"See the new Fox poll that had Bernie up a lot in New Hampshire?," Briggs asked. "No wonder they're in attack mode. Secretary Clinton and her team are getting nervous and nasty because the so-called inevitable nominee anointed by the establishment eight months ago doesn’t look so inevitable anymore."

A new Fox News poll has Sanders up 50-37 in New Hampshire.

Sanders’ record on gun control has come under even higher scrutiny since President Obama’s recent New York Times op-ed on the need for gun control. “I will not campaign for, vote for or support any candidate, even in my own party, who does not support common-sense gun reform,” President Obama wrote. Some -- including the Clinton campaign -- thought he was subtly referring to Sanders.

“It’s not every day that a sitting president is unable to commit to supporting a potential nominee of his party,” Clinton Press Secretary Brian Fallon said today.

But Sanders’ campaign said they never considered the idea that Obama was referring to their candidate.

“Until someone asked about it, it never even occurred to me it was applied to us, because we see ourselves on the same side as Barack Obama,” Weaver said today.

Weaver emphasized that there is "zero daylight" between Sanders and the President on gun control, a statement Clinton staffers emphatically refuted.

Speaking on MSNBC today, Sanders reiterated his support for the measures the President wants to implement.

"I support what the President is doing,” Sanders said. "There are a lot of candidates running in the house and the senate who may be opposed to sensible gun control legislation. I happen not to be one of them."