The Swift Boat Veterans ads in 2004 attacking John Kerry's exploits in Vietnam, the infamous Willie Horton ad in 1988 that portrayed Mike Dukakis as soft on crime, and the notorious 1992 "Read my lips" spot that focused on the then-President George Bush breaking his earlier pledge to not raise taxes.
All three ads may be derided by the pundits as negative advertising, but there is little doubt that they worked: They helped turn the elections against the targeted candidates.
The ads were products of opposition research, nuggets of damaging information about political candidates uprooted by their opponents to damage their reputation or credibility in the eyes of the voters.
And one of their prime manipulators has finally stepped out from the shadows to reveal his tactics and role in tipping numerous elections around the country over the last decade and a half.
Stephen Marks, an opposition research specialist for more than 12 years, worked on some of the most competitive bare-knuckles elections in recent years, including the 1996, 2000 and 2004 presidential elections, the second North Carolina Senate race between Jesse Helms and Harvey Gantt in 1996, and the Georgia Senate race between Max Cleland and Guy Millner.
He also dug up dirt for scandal-plagued lobbyist Jack Abramoff and his partner Mike Scanlon, oil company Koch Industries, and he helped former House Majority Leader Tom DeLay look up negative info on his nemesis, Texas prosecutor Ronnie Earle, who was targeting DeLay for campaign finance violations.
Marks, who recently retired from his career in opposition research, tells all in his new book, "Confessions of a Political Hitman: My Secret Life of Scandal, Corruption, Hypocrisy and Dirty Attacks That Decide Who Gets Elected (And Who Doesn't)."
Although he doesn't literally murder people, Marks writes that "I assassinate them with their own words and deeds, digging dirt wherever I can find it." And that dirt includes politicians' own records as public officials and professionals, their financial records and their personal lives.
Marks makes no apologies for his career. "Whether negative stuff is good or bad, people have a right to know," Marks tells ABCNEWS.com. "You have to back up your info with facts, unlike positive ads that tend to focus on promises. The researchers give the candidates the straight facts, and if they want to take those facts and skew them and take them out of context, that's on them."
After years of realizing after an election that he'd actually been working for "the bad guy" against "the good guy," Marks grew disillusioned with the Republican Party and what he calls its hypocrisy on "family values" issues.
"A lot of me was going in idealistic, as a true believer, only to find out that a lot of these guys, once they get the trappings of power, it's very hard for them to give that up," he explains. "The Republicans were no different form the Democrats when they were in full control, and I thought they wouldn't make the same mistakes or have the same arrogance."
Among his proudest accomplishments was his creation of an anti-Gore ad in 2000 that showed Gore defending the Rev. Al Sharpton followed by footage of Sharpton telling college students to "off the pigs" (or kill cops) and Sharpton calling America's Founding Fathers the "scum of Europe."