go after the opponent's strengths

I've started to hear political ads on the radio here in Washington State. The couple that I have heard so far seem to be well-done - since they focus on just one or two negative points of the opponent. One idea for a radio or tv commercial for Mitt would be, instead of focusing on a negative point about the opponent, state the good things about the opponent. "Mayor Guiliani succeeded in doing this, this, and this in New York." Then point out similar things Mitt has accomplished, but has done either better, more efficiently, with greater impact, or with longer-lasting effects.