Picking up the backing of the gun-control group CeaseFirePA in a war of endorsements, Democratic U.S. Senate nominee Katie McGinty pledged Wednesday to work with Pennsylvania sportsmen and hunters on gun measures if she is elected.

McGinty said her Republican rival, Sen. Pat Toomey, views gun control "as a political calculation, as compared to a matter of principle," and slammed him for not acting on gun measures since he and Sen. Joe Manchin (D., W. Va.) cosponsored a failed bill for background checks in 2013.

"I would bring responsible sportsmen and hunters from Pennsylvania to the table and work with them to bring new partners [and] alliances, and frankly, defuse the vitriol from this issue," McGinty told reporters in a conference call.

Her remarks came two days after Toomey, who is seeking a second term, was endorsed by Americans for Responsible Solutions, the gun-safety group founded by former Rep. Gabby Giffords, the Arizona Democrat shot in the head during a gunman's 2011 rampage. Toomey also has been endorsed by former New York City Mayor Michael Bloomberg and his gun-control-focused PAC, Independence USA.

"The gun-safety organizations that are serious about achieving bipartisan results, such as those of Gabby Giffords and Michael Bloomberg, are supporting Pat Toomey," Toomey spokesman Ted Kwong said in response to the CeaseFirePA endorsement.

That group's director, Shira Goodman, said during the call that McGinty would be a "constant, consistent leader" on gun issues, and is "the candidate, we believe, who will make gun violence prevention a cornerstone of her work in Washington."

The gun groups that have endorsed Toomey are looking to line up Republican support on an issue on which Democrats already concur.

More important, McGinty said, would be electing enough Democrats to tip the Senate majority.

"Democratic leadership would bring a focus and priority on this critical issue, and I am certain that we would build the coalition needed to see progress on these critical issues," she said.

CeaseFirePA surveyed both candidates before and after the primary election, Goodman said. McGinty supported the group's positions: expanding background checks, regulating assault weapons and high-capacity magazines, banning terrorism suspects from buying weapons, and supporting a bill from Sen. Bob Casey (D., Pa.) to prohibit people convicted of misdemeanor hate crimes from buying guns.

Toomey, Goodman said, responded with support for background checks, but not for the group's full agenda.