Do Political TV Ads Work?

Can you recall ever having your mind changed by a candidate based on an ad? Obviously, advertising works, to some extent: I just switched from Cascade dishwasher pods to Finish dishwasher pods after seeing a commercial which informed me that many other people had already done so, and made no other claims.

But, apart from thinking less of a candidate based on his (or her, but mostly his) Jim (The Hammer) Shapiro-esque TV spots, what works? What would work? If you were on the Obama campaign (or on the Romney campaign, or on the really-endearing Gary Johnson campaign), how would you go about attracting the readers of The Hairpin?