THE new FBI probe into Hillary Clinton’s emails could derail her presidential campaign and open the White House door to Donald Trump, it was claimed yesterday.A new national poll revealed he has slashed her lead to four points – 48 per cent to 44 – with nine days remaining before Americans go to the polls. And, even before the FBI investigates “bombshell” new evidence linked to Mrs Clinton’s alleged sending of classified information via her private computer server, senior Democratic figures fear the scandal will swing undecided voters to Trump.Party strategist Jim Manley, a former aide to Senate minority leader Harry Reid, admitted: “The damage has been done. House Republicans and the Trump campaign are not going to let this go.” Trump himself jubilantly described the fresh FBI probe as being “bigger than Watergate” – a reference to the 1970s political corruption scandal that brought down President Richard Nixon. At a Friday night rally in Cedar Rapids, Iowa, he added: “The FBI would never have reopened this case at this time if it were not an egregious criminal offence. Justice will prevail.”Carl Bernstein, one of the journalists who broke the Watergate story in the Washington Post, said of the investigation: “There’s no question that the emails have always been the greatest threat to her candidacy. This is her Achilles’ heel.“Her conduct in regard to them is really indefensible and – if there’s going to be more information coming out – this is the one thing that could really affect this election.” In a US television interview, he added: “We don’t know what this means yet except that it’s a real bombshell. It is unthinkable that the director of the FBI would take this action lightly."FBI Director James Comey had recommended earlier this year that the Department of Justice should not prosecute Mrs Clinton over e-mails sent via her private server when she was Secretary of State in Barack Obama’s government between 2009 and 2013. But on Friday he announced the bureau had re-opened its investigation after obtaining new emails that “appear pertinent”. These stem from a separate inquiry into disgraced former Democratic congressman Anthony Weiner, who in September was accused of sending obscene text messages and images to a 15-year-old girl. Weiner’s estranged wife is Huma Abedin, vice chairwoman of Mrs Clinton’s election campaign and one of her most senior aides and personal confidantes. It was while looking at Weiner’s laptop, which he shared with his wife, that emails possibly relevant to the FBI probe into Mrs Clinton’s handling of classified information were found.The discovery prompted a gleeful response from Republican rival Mr Trump. At a rally in New Hampshire, he said: “Hillary Clinton’s corruption is on a scale we have never seen. “We must not let her take her criminal scheme into the Oval Office.” In July last year Trump hit out during a news conference, saying: “I don’t like Huma going home at night and telling Anthony Weiner all of these secrets.” He later claimed that Weiner would “tell the world” about Hillary Clinton’s emails, tweeting: “It came out that Huma Abedin knows all about Hillary’s private illegal emails. Huma’s PR husband, Anthony Weiner, will tell the world.” The disgraced congressman has not spoken out about Clinton’s emails. Abedin left Weiner in August after it emerged he had sent an explicit photographs of his crotch to another woman. That was his third involvement in so-called sexting, following two more scandals in 2011 and 2013 when he admitted sending sexually explicit photographs to women.