Campaign media advisers say that waging a modern presidential ad campaign is like swinging a giant hammer at a tiny nail. Almost all of the commercials are aimed at a minority of a minority of voters: the few who haven't yet made up their minds in a handful of battleground states. A Gallup poll of likely voters in 12 such swing states in early May found that only 7 percent described themselves as undecided. And the number shrinks the closer it gets to Election Day.
TV ads affect "a narrow sliver of voters in a very narrow segment of the country," says Steve McMahon, who directed former Vermont Gov. Howard Dean's primary advertising in 2004 and the Democratic National Committee's general-election ads in 2008. "Those people receive information in lots of ways, and ads are just one way."
But McMahon says advertising is a key part of a candidate's communications strategy. "All those [messages] create an orchestra. If your campaign is working, all the pieces come together," he said.
McMahon says the great danger for any campaign is to lose your "share of voice" — the ability to match or exceed an opponent's advertising. Such imbalances could crop up more frequently in this election because of unlimited spending by super PACs.
While the bulk of 30-second ads will be directed to a limited number of cities, broadcast stations and programs, the candidates have better ways than ever to target different sets of voters. Local cable stations make it possible to reach narrow subsets of voters, such as Latinos watching Telemundo in Tampa or African Americans watching BET in northern Ohio. Although the Internet is a growing source of targeted campaign advertising, it remains a distant second to traditional broadcasting, said Wesleyan Media Project's Fowler. In part, this is because TV ads are passive, whereas Internet ads require a viewer to click and play — a potential barrier, she notes.