Twenty-eight female guards were unfairly dismissed by a security company because the client‚ Metrora.
WASHINGTON - Smears and slurs are flying in the 2008 White House race, and with polls narrowing and nominating contests six weeks away, experts predict the rough stuff has just begun.
Candidates are upbraiding party rivals and savaging foes in the opposite party. Democrats Hillary Clinton and Barack Obama, fresh from a brace of debate showdowns, are increasingly turning their guns on one another.
The former first lady is also target number one for Republicans, when they are not mocking one another over immigration policy.
"You can't have a campaign without negativity," said Professor Emmett Buell, of Denison University, Ohio.
"By definition, it is an attempt to make the argument you are a superior choice to your opponents, you have to criticise [them] and extol yourself."
The temperature of the Democratic race hit boiling last weekend, with a conservative columnist suggesting front-runner Clinton had "scandalous" information on Obama. Obama immediately called on Clinton to dish the dirt, or disown it, escalating a row which ended with her camp accusing him of falling for Republican tricks.
Clinton jabbed Obama with withering sarcasm on Tuesday, mocking his suggestion that his boyhood years living in Indonesia had given him a more nuanced world view.
"Voters will judge whether living in a foreign country at the age of 10 prepares one to face the big complex international challenges we face," she said.
A third Democrat, John Edwards, also got into the action.
"Now we know what Senator Clinton meant when she talked about throwing mud - when it comes to mud, Hillary Clinton says one thing and throws another," he said.
The Clinton-Obama spat rumbles on because both candidates want it to.
Obama is using it to brand Clinton a product of a warped Washington political culture, while she claims he is too inexperienced to be president.
"As the contest gets closer and closer to the January kick-off, you are going to see harsher exchanges, because the stakes are high and Clinton and Obama have a lot of money," said Professor John Geer, of Vanderbilt University, Tennessee.
While the Clinton-Obama wars are in the open, a more vicious form of attacks is brewing in the key lead-off state of Iowa, with several reports of "push-polling" - a telephone call to voters to highlight a perceived negative aspect of a politician's character.
Republican Mitt Romney blasted "un-American" push-poll slurs about his Mormon faith, a perceived liability among Christian evangelical voters.
Negative campaigning is as old as US politics itself, and dates from the days when attacks travelled by political pamphlet rather than YouTube video.
In the 1988 campaign, former president Bush seized on video of an ill-at-ease Democratic rival Michael Dukakis in a battle tank as a narrator told viewers they couldn't risk him as commander in chief.
In the 2004 presidential battle, Republicans used footage of Democrat John Kerry on a windsurfer, claiming he was indecisive: "John Kerry, whichever way the wind blows."
Kerry also provided a masterclass on how not to fight back, taking the high road after adverts impugned his Vietnam war service. - Sapa-AFP