The positives of negative campaigning.

OUR COVER IMAGE this month is taken from the Citizen Kane of political attack ads: the infamous "daisy" spot created for Democratic incumbent Lyndon Johnson's campaign during the 1964 presidential election. Without ever mentioning Republican challenger Barry Goldwater by name, the spot was an unmistakable response to the Arizona senator's talk of using "low-yield" atomic weapons to end the communist insurgency in Vietnam.

The ad, in which a young girl pulls the petals off a flower until a mushroom cloud fills the screen, effectively painted Goldwater as a mad bomber and helped lead to his crushing defeat at the polls. More impressively, the ad appeared just once in prime time, during the NBC Movie of the Week, on September 7, 1964. The commercial was so controversial--and the Goldwater campaign so outraged--that LBJ's crew never had to pay to run it again, instead relying on news programs to air the spot endlessly and discuss its merits and flaws. American political communication would never be the same. (You can view that ad and many other campaign commercials online at livingroomcandidate.com.)

The daisy spot didn't just usher in an age of attack ads. It ushered in an age of attacks on attack ads, of pious lamentations that political discourse has gotten too shrill, too divisive, too partisan. A decade ago, as the presidential race between Bill Clinton and Bob Dole shuffled along with all the speed, grace, and dignity of Frankenstein's monster, then-House Minority Leader Dick Gephardt (D-Mo.) summed up the conventional wisdom that still dominates Beltway thinking. "We're destroying a process with negative advertising, which is giving everybody a very cynical attitude about politics and politicians," crabbed the Show Me State's multiple loser in the presidential-nomination sweepstakes. In a similar vein, The Washington Post's eminent columnist David Broder has blamed "the polarization of American politics" on "the increasingly negative tone and content" of 30-second TV ads. Some political scientists even argue that negative campaigns keep voters at home.

Veteran political reporter David Mark takes a very different position in this month's cover story, "Attack Ads Are Good for You!" (page 22). Negative campaigning may not be pretty, argues the author of this year's Going Dirty, but it provides citizens with a wealth of relevant and surprisingly substantive information crucial to an informed electorate. Thanks to attack ads, writes Mark, voters gain invaluable insights "about prospective elected officials if they are willing to process multiple sources of information and draw their own conclusions." And, he continues, there's little reason to believe that bruising, even ugly, battles keep citizens away from the polls. Indeed, as the last presidential race shows, highly partisan races tend to boost voter participation rates.

So as the midterm election cycle kicks into high gear, take a moment to savor attack ads. You'll be a better voter the more closely you pay attention.