Any information about a candidate that can be demonstrated is the background noise in a foreground contest by the combatants themselves. While Pres. Bush will not push the photo and the facts of Kerry's communist sympathies, there are other dissemination methods that get valid information into the hands of voters. If presented correctly, they will notice it.
Vets who detest Fonda will NOTICE the picture of Kerry/Fonda and they will file it away as ONE of the facts about Kerry that they know.