The fact that this is Sam Nunn's daughter and the organization she ran was GHWB's organization both protect her here - as does her classy demeanor and appearance when she speaks out herself - with revulsion against the ad. An ad her opponent signed off on.
I suspect that in ANY election, there are pools of people on both sides that will stay where they are no matter what. Here the key is getting them out. To Democrats, this unfair attack should echo with past unfair attacks - like the attack in neighboring SC on Clealand. To Republicans, it could make them a little queasy - which might make them a little less likely to vote. (Those that believe the charge are strong RW Republican votes that were already going to happen.)
To the people in the middle, you have an understated, professional woman - who seems very likable here - defending work that she, the daughter of a very respected conservative Democrat did for a BUSH charity. If they were considering Perdue, I hope that he now looks like a bully and a swiftboater. I can't help thinking this sways many on the fence - because it IMPLICITLY defines Perdue by his own actions as a creep - while emphasizing her own positives, including being bipartisan.