Dem's campaign manager quits after video shows candidate secretly backing gun ban

The campaign manager of a Democrat seeking a U.S. House seat in upstate New York quit the campaign Tuesday, after a video showed the candidate saying she wouldn't publicly endorse a ban on certain firearms -- for fear that she’d lose the election.

Mike Szustak, who since April had run the campaign of candidate Tedra Cobb, told the Watertown Daily Times that he’s no longer part of Cobb's bid to unseat Republican incumbent Elise Stefanik in New York's 21st Congressional District.

The departure follows revelations that Cobb won’t publicly state that she favors banning assault rifles. The video was first revealed by the Washington Free Beacon. Fox News also reported on the video.

NEW YORK DEM RUNNING FOR US HOUSE SEAT BACK GUN BAN – BUT WON’T SAY SO PUBLICLY

"When I was at this thing today, it was the first table I was at, a woman said, ‘How do you feel about assault rifles?' And I said they should be banned," Cobb is heard telling a group of teens in the video.

"And I said, you know, people were getting up to go, to go get their lunch because it was a buffet, and I just said to her, 'I want you to know, Cindy, I cannot say that,” she added.

"When I was at this thing today, it was the first table I was at, a woman said, ‘How do you feel about assault rifles?' And I said they should be banned."

- Tedra Cobb

The Democrat went on to explain that she cannot publicly come out in support of a gun ban as that will doom her election chances.

"And she said, ‘Well, I want you to,' and I said, ‘I won't win,'" Cobb said. "I said Moms Demand [Action] says, and Tricia Pleau [member of the gun-control group Moms Demand Action] said, ‘Do not say that you want an assault rifle ban because you will not win.'"

Cobb has a platform for addressing gun violence nationwide, including the expansion of universal background checks and banning of bump stocks -- devices that make a semiautomatic weapon fire like an automatic weapon. But none of her official proposals suggest banning any type of firearms.

The Republican Party jumped on the issue last week, issuing a stark attack on Cobb, calling her “wildly out of touch” and accusing her of “lying to voters.”

"Tedra Cobb knows that she's wildly out of touch with the district, so she's desperately trying to hide her liberal agenda from voters," Chris Martin, regional press secretary of the National Republican Congressional Committee, told the Free Beacon.

“First, she was forced to admit that she raised taxes over 20 times [as a St. Lawrence County official], and now she's being exposed for lying to voters about her support for an assault weapons ban and taking guns away from law-abiding citizens,” he added.

Lukas Mikelionis is a reporter for FoxNews.com. Follow him on Twitter @LukasMikelionis.