The Progressive Change Campaign Committee began an ad campaign Wednesday attacking Sen. Max Baucus (D-Mont.) for his vote against gun buyer background check legislation, even after he announced he would not run for reelection in 2014.

The PAC is spending more than $50,000 to air the ad for a week on broadcast and cable television in Montana and on MSNBC and CNN in Washington.

"Im a grandmother, a hunter and a gun owner. Ive been the victim of a home invasion. I hid my girls in a closet, called for help, aimed my handgun at the door and waited," says narrator Claire Kelly. "Guns can protect us but were less safe with guns in the wrong hands. Seventy-nine percent of Montana voters support background checks. So why did Senator Max Baucus vote against us? Senator Baucus, now that youre retiring, please put Montana first."

Baucus announced his retirement on April 23, six days after voting against bipartisan Manchin-Toomey legislation that would have expanded background checks for gun buyers. He explained his vote with one word -- "Montana."

The bill fell six votes short the 60-vote threshold needed for Senate passage. Sen. Joe Manchin (D-W.V.) said on Sunday he didn't think the measure was dead. Sen. Pat Toomey (R-Pa.) told Pennsylvania reporters Tuesday that it was unlikely to get the votes anytime soon.