The FBI's decision to reveal a probe into recently uncovered emails related to the Hillary Clinton server investigation wasn't illegal, but it was unprecedented and could damage the law enforcement agency more than it does Clinton, experts told CNBC. Andra Gillespie, a political science professor at Emory University, said an FBI director had never before unveiled an election-impacting investigation so close to the poll date. America is due to vote on its next president on November 8. "While it's not technically illegal, it does violate some longstanding practices so this actually raises the specter of the politicization of the FBI," Gillespie told CNBC's "Squawk Box" on Monday. FBI Director James Comey's wrote to U.S. lawmakers on Friday that the bureau was looking at emails discovered on devices used by former congressman Anthony Weiner and Clinton aide Huma Abedin, as part of its investigation into Weiner's alleged "sexting" of a teenage girl. The emails were between Abedin, who is Weiner's estranged wife, and the Democratic nominee. Comey said that the emails appeared to be pertinent to an investigation the FBI previously conducted into Clinton's use of a personal server to exchange emails while she was the country's secretary of state. Comey's disclosure of the emails sparked fierce criticism, particularly from Clinton herself, who called the move an "unprecedented" departure from FBI policy.

On Sunday, as the FBI obtained a warrant to search the emails, Democratic Senate Minority Leader Harry Reid also rounded on Comey, saying in a letter that the FBI boss had "demonstrated a disturbing double standard for the treatment of sensitive information, with what appears to be clear intent to aid one political party over another." Reid added that his office determined that Comey may have violated the Hatch Act, which bars government officials from using their authority to influence elections. Steve Schmidt, who was the campaign strategist on Republican Senator John McCain's presidential campaign in 2008, said Comey's move would hurt the FBI. "There is nobody in America who is undecided on the question of Secretary Clinton's emails." Schmidt, who is now vice chairman of public affairs at public relations firm Edelman, told CNBC's "The Rundown." "So this information at the end of the day, what it is most about, is really the damage Director Comey has done institutionally to the FBI." Adding to the questions surrounding the FBI's decision to release information about the investigation was the fact that the new revelations did not break new ground, Gillespie said. The academic did not expect the revelations, meanwhile, to significantly impact the election outcome.

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