It is doubtful that this was the only reason that Dole lost against Hagan but it does show that it making slurs against atheists in public is no longer being considered acceptable in some social spheres. Within a very short time of Dole airing her infamous ad, her political opponent soon began getting several thousand campaign contributions during a campaign fundraiser in Boston. These contributors were composed of not only disgruntled atheists, but also religious people who thought that Dole's ad was highly offensive and inappropriate even for a campaign ad.
Historically, in public polls atheists are regarded as being the least popular minority by the general populace in regards to being fit for political office. This is why "under God" was added during the Pledge of Allegiance during the red scare in order to distinguish Americans from the "godless" Soviet Union. I am glad to see that people are beginning to challenge the negative perception that atheists have in the US and I hope that atheism will no longer be regarded as a dirty word by many people.