
Political dirty tricks —
Aides and appointees of New Jersey Gov. Chris Christie have been accused of closing lanes on the George Washington Bridge to punish Fort Lee Mayor Mark Sokolich, pictured, for not endorsing Christie for re-election. If true, this wouldn't be the first time an American politician was targeted with dirty tricks -- the practice goes back as far as running for office. Click through to see other examples of less-than-ethical campaign tactics.

Political dirty tricks —
Prostitution allegations: Sen. Robert Menendez of New York denied that he paid a woman for sex, saying allegations that he did were part of a smear campaign. "Any allegations of engaging with prostitutes are manufactured by a politically motivated right-wing blog and are false," Menendez's office said in a statement. The alleged prostitute later filed a notarized statement saying she had never even met Menendez.

Political dirty tricks —
Fake letters: Sen. Edmund Muskie of Maine, running for president, was expected to do well in the 1972 Democratic primary in neighboring New Hampshire. But the Manchester Union-Leader published a letter alleging that Muskie condoned the use of the term "Canuck," a derogatory term used against French-Canadians. Muskie denied the charge but still suffered at the polls in the early primary, which doomed his chances. The Washington Post later reported that the letter was a hoax and was probably written by Ken Clawson, deputy White House communications director in the Nixon administration.

Political dirty tricks —
Watergate: The break-in at the Watergate office complex was just the tip of the iceberg in regards to what was going on within President Nixon's re-election campaign in 1972. The Nixon machine was hell-bent on destroying its opponents, and Donald Segretti, pictured, was one of the primary dirty tricksters. The Nixon operative printed fliers that attacked Muskie on his stance against Israel, and he placed them outside synagogues. He also pitted Democrats against one another in a tactic he called "rat-f---ing," like the letter addressed from Citizens for Muskie that accused Democratic primary rival Sen. Henry Jackson of being a homosexual and fathering an illegitimate child with a teenager. Segretti was one of several Nixon operatives who ended up in jail.

Political dirty tricks —
Doctored photos?: Ross Perot was the first major third-person candidate in modern American politics to mount a serious run for the White House. His plainspokenness got attention, and his platform appealed to the far right. Most of all, he was seen as a threat to split the Republican vote with President George H.W. Bush, who was running for his second term. Despite the energy in his campaign, Perot dropped out of the race, claiming that Republican operatives were about to smear his daughter with doctored photos and try to ruin her wedding. Perot never explained what the photograph purportedly showed.

Political dirty tricks —
The mystery of Alvin Greene: When Alvin Greene suddenly won the Democratic primary for U.S. Senate in South Carolina, experts asked, "Who?" Greene didn't campaign, had no political experience and was rarely seen in public. A CNN interview led to more questions of whether Greene, pictured, was intellectually capable of running a viable campaign. Others felt that Greene was planted by Republican Sen. Jim DeMint, who was running for re-election. Greene was cleared by the South Carolina Law Enforcement Division before he lost overwhelmingly to DeMint.

Political dirty tricks —
Swift-boating: Before John Kerry, far right, was elected senator, he won the Purple Heart and a Bronze Star for his service in Vietnam and later protested against the war. When he ran for president in 2004, he spoke out against the Iraq War. Although Kerry was seen as the underdog in the race, he was gaining momentum before a political ad released by the group known as Swift Boat Veterans for Truth accused Kerry of speaking ill of his fellow veterans and lying to get his medals. Kerry first tried to ignore the ads before denying the allegations, but by then the ads -- and Kerry's avoiding them -- stopped whatever momentum was building.