
Gun control advocates have funded an ad campaign that criticizes Sen. Kelly Ayotte's vote on a gun control measure. She is facing re-election in 2016. (Associated Press)

Gun control advocates have funded an ad campaign that criticizes Sen. Kelly Ayotte's vote on a gun control measure. She is facing re-election in 2016. (Associated Press)

** FILE ** Senate Armed Services Committee member Sen. Kelly Ayotte, R-N.H., questions former Nebraska Republican Sen. Chuck Hagel, President Obama's choice to lead the Pentagon, during his confirmation hearing on Capitol Hill in Washington, in this Jan. 31, 2013 file photo. A woman whose mother was killed in last year's school shooting in Newtown, Conn., confronted Ms. Ayotte Tuesday, April 30, 2013, during the senator's first public appearance in New Hampshire since voting against gun control legislation. (AP Photo/J. Scott Applewhite, File)

** FILE ** Senate Armed Services Committee member Sen. Kelly Ayotte, R-N.H., questions former Nebraska Republican Sen. Chuck Hagel, President Obama's choice to lead the Pentagon, during his confirmation hearing on Capitol Hill in Washington, in this Jan. 31, 2013 file photo. A woman whose mother was killed in last year's school shooting in Newtown, Conn., confronted Ms. Ayotte Tuesday, April 30, 2013, during the senator's first public appearance in New Hampshire since voting against gun control legislation. (AP Photo/J. Scott Applewhite, File)

**FILE** Sen. John McCain (right) of Arizona, the ranking Republican on the Senate Armed Services Committee, and fellow committee member Sen. Kelly Ayotte (left), New Hampshire Republican, listen as Sen. Lindsey Graham, South Carolina Republican, speaks during a news conference on Capitol Hill in Washington on Nov. 14, 2012. (Associated Press)

Sen. Kelly Ayotte, New Hampshire Republican, and Sen. Lindsey Graham, South Carolina Republican, have been vocal opponents about the narrative of the Obama administration in the wake of the Sept. 11 attacks on the consulate in Libya. (Associated Press)

Sen. Kelly Ayotte, New Hampshire Republican, and Sen. Lindsey Graham, South Carolina Republican, have been vocal opponents about the narrative of the Obama administration in the wake of the Sept. 11 attacks on the consulate in Libya. (Associated Press)