There is only one reason campaigns spend so much time and effort on political attack ads. They work. While they may work to varying degrees of effectiveness, there can be no doubt that, at least at some level, they do work.
While political science majors write reports arguing both sides and studies report findings both for and against the effectiveness of political attack ads, campaigns see it clearly. Many associated with the U.S. presidential campaign of John Kerry in 2004 blamed attack ads for costing their candidate the election. That year, a group called Swift Boat Veterans for Truth ran a number of ads questioning Kerry's service in Vietnam.
Political attack ads, especially through the medium of television, had their beginning during the 1964 election between Lyndon Johnson and Barry Goldwater. In an ad simply titled "Daisy," a little girl is seen counting petals off a flower. As the scene zooms in on her eye, a nuclear bomb explodes. Johnson then provides a voice over promoting peaceful means of addressing conflicts. Johnson's intention was clear. Goldwater was known as a war hawk that advocated the use of nuclear weapons in Vietnam and Russia.
Johnson won the election against Goldwater in a landslide. Many political analysts have credited that ad as a turning point in the election. While Johnson may have won the election without the commercial, the margin of victory was largely attributed to that ad.
However, while millions of dollars can be spent on negative campaigning through the form of political attack ads, campaigns must be careful in their use. Running political attack ads that are seen as attacking a person's character or personal issues can backfire. Ads must focus on issues related to the campaign in order to achieve maximum effectiveness.
Political attack ads also run the risk of bringing notoriety to the other candidate. There is a reason why product ads seldom mention other brands; they do not want to draw attention to them. This is why such ads often run comparing themselves to "the other leading brand." However, most political ads do mention their opponents because the construction of the ad would be too awkward without doing so.
While most people in democratic nations deplore political attack ads, if done correctly, they can produce a desired effect for a campaign. Candidates authorize millions of dollars to be spent on this tactic simply because it can produce an immediate, and lasting, benefit. In the end, political attack ads will continue to be used, despite the complaints, as long as candidates believe they get results.