A smear campaign, smear tactic or simply smear is a metaphor for activity that can harm an individual or group's reputation by conflation with a stigmatized group. Sometimes smear is used more generally to include any reputation-damaging activity, including such colloquialisms as mud slinging.
Common targets are public officials, politicians, and political candidates. Smear campaigns are often based on information gleaned from opposition research conducted by paid political consultants. To a lesser degree, the term can refer to an attempt to damage a private person's reputation; for example, during a trial, the opposing counsel may attempt to cast doubt on the reliability of a witness.
Smear tactics differ from normal discourse or debate in that they do not bear upon the issues or arguments in question. A smear is a simple attempt to malign a group or an individual and to attempt to undermine their credibility.
Smears often consist of ad hominem attacks in the form of unverifiable rumors and are often distortions, half-truths, or even outright lies; smear campaigns are often propagated by gossip spreading. Even when the facts behind a smear are shown to lack proper foundation, the tactic is often effective because the target's reputation is tarnished before the truth is known.
Richard H. Davis of the Boston Globe describes a smear campaign this way;
The premise of any smear campaign rests on a central truth of politics: Most of us will vote for a candidate we like and respect, even if we don't agree with him on every issue. But if you can cripple a voter's basic trust in a candidate, you can probably turn his vote. The idea is to find some piece of personal information that is tawdry enough to raise doubts, repelling a candidate's natural supporters.
The Watergate scandal that brought down President Nixon was the use of government tools and resources for a partisan smear campaign.
Smear campaigns go as far back as The Dusky Sally stories first circulated in 1802 by a political enemy of Thomas Jefferson named James Callender.
In the Sept. 1, 1802, issue of the Richmond Recorder, he wrote the first of many assaults on the president’s character: "It is well known that the man whom it delighted the people to honor, keeps and for many years has kept as his concubine, one of his own slaves. Her name is SALLY. The name of her eldest son is TOM. His features are said to bear a striking although sable resemblance to those of the President himself." [capital letters in the original] He went on to claim that Jefferson first had his way with Sally while he was ambassador to France, and that she had returned pregnant to Monticello.
The George W Bush 2000 presidential campaign used a similar smear campaign against Presidential candidate John Mccain:
Rove invented a uniquely injurious fiction for his operatives to circulate via a phony poll. Voters were asked, "Would you be more or less likely to vote for John McCain...if you knew he had fathered an illegitimate black child?" This was no random slur. McCain was at the time campaigning with his dark-skinned daughter, Bridget, adopted from Bangladesh.
The Bush administration was famous for its smear campaigns including treasongate and the "outing of Valerie Plame. Bush operatives smear campaign against presidential candidate John Kerry was so insidious it that it engendered a new political phrase called " swiftboating "
The Arkansas Project was a series of investigations (mostly funded by billionaire Richard Mellon Scaife) that were initiated with the intent of smearing the presidency of Bill Clinton.
Bill Clinton was himself accused of a smear campaign against presidential candidate Barrack Obama
President Obama has been the subject of so many smears that there is a full time website devoted to debunking them,
Smears are also effective in diverting attention away from the matter in question and onto the individual or group. The target of the smear is typically forced to defend his/her reputation rather than focus on the previous issue.