Six months after it began, the federal investigation into Hillary Clinton Hillary Diane Rodham ClintonHillicon Valley: FBI chief says Russia is trying to interfere in election to undermine Biden | Treasury Dept. sanctions Iranian government-backed hackers The Hill's Campaign Report: Arizona shifts towards Biden | Biden prepares for drive-in town hall | New Biden ad targets Latino voters FBI chief says Russia is trying to interfere in election to undermine Biden MORE’s private email server shows no signs of slowing down.

Former FBI officials said the length of the probe is not unusual and speculated that a decision on whether to file charges against Clinton or her top aides could come later this year, during the heat of the general election campaign.

ADVERTISEMENT

“I don’t know that there’s any magical cutoff date,” said Ron Hosko, the FBI’s former assistant director of the criminal investigative division and a 30-year veteran of the bureau.

For Democrats, the extended investigation has become a source of some anxiety, with Republicans gleefully raising the prospect of the Democratic presidential front-runner being indicted.

“It does give pause to Democrats who are concerned that there may be another shoe to drop down the road,” said Andrew Smith, a political science professor at the University of New Hampshire.

The government has been examining the former secretary of State's private email server since last July, when the inspector general for the intelligence community issued a security referral noting that classified information could have been mishandled.

That referral came months after Clinton acknowledged that she had exclusively used a personal email address housed on a private server during her tenure as secretary.

The scrutiny of her email practices has mounted since then, with more than 1,300 emails that passed through her server found to contain information that has since been classified, some at the highest levels.

The State Department and Clinton’s campaign contend that none of the information in the emails was classified when it was originally sent, and they have portrayed the matter as an interagency dispute.

The FBI and Justice Department have refused to discuss the details of their investigation and declined to comment to The Hill.

Officials have indicated that the bureau is not targeting Clinton specifically, however, but is investigating whether any information on her account was mishandled. Earlier this month, Fox News reported that the FBI had expanded its inquiry to examine how the State Department’s work intersected with the Clinton family foundation.

In December, FBI Director James Comey pledged that the probe would be “competent,” “honest” and “independent.”

“We don't give a rip about politics,” he told a Senate committee.

Yet the FBI is well aware of the high political stakes surrounding the investigation.

“I think the clock ticks louder every day,” said Hosko, who is the president of the Law Enforcement Legal Defense Fund. “I’m sure they’re all incredibly sensitive to it.”

President Obama has downplayed Clinton’s email setup, claiming that it was “not a situation in which America’s national security was endangered.”

Multiple former officials, lawmakers and lawyers have said they are confident that Comey, who is a Republican, will not let the presidential campaign influence the FBI’s investigation.

Yet many conservatives worry that even if the bureau comes up with sufficient evidence that Clinton broke the law, the Justice Department will decline to press charges. In response, some have pressed for a special prosecutor to be appointed, or for the FBI to pledge to release whatever evidence it digs up.

So far, Democrats have publicly shrugged of the threat of criminal action by painting it as a partisan attack from Republicans.

Clinton’s top rival for the Democratic presidential nomination, Sen. Bernie Sanders Bernie SandersMcConnell accuses Democrats of sowing division by 'downplaying progress' on election security The Hill's Campaign Report: Arizona shifts towards Biden | Biden prepares for drive-in town hall | New Biden ad targets Latino voters Why Democrats must confront extreme left wing incitement to violence MORE (I-Vt.), channeled the feelings of Democrats in October when he told Clinton during a debate that “the American people are sick and tired of hearing about your damn emails.”

But Clinton will have to confront the issue more forcefully if charges are filed.

And should Clinton win the nomination, the topic is sure to be an issue in the general election campaign — even if no indictment is handed down.

A fight over the emails then could weaken Democratic enthusiasm and turn off swing voters, some analysts predicted.

“More likely, it’s going to sour some of those folks in the middle,” said Doug Roscoe, a political science professor at the University of Massachusetts Dartmouth.

“Having to be in the news talking about this investigation takes her off message,” he added.

It might not be Clinton herself who faces the music for any potential crime, however.

The former secretary of State did not appear to send most of the emails now marked classified. Instead, they were largely sent or forwarded to her by aides.

“It’d be a lot harder to make a criminal charge for having received [classified] information," said Bradley Moss, a lawyer who specializes in national security and protection of classified information

“If I’m in Clinton’s campaign, I’m more worried if am Cheryl Mills, Huma Abedin or Jake Sullivan than if I’m Hillary Clinton,” Moss said. Mills, Abedin and Sullivan were all top aides of Clinton’s at the State Department. Abedin and Sullivan continue to hold high positions in Clinton’s presidential campaign.

“The sloppiness and the complete fundamental failure to comply with any aspect of operational and informational security is what puts them at risk,” Moss said. “You just can’t do that that many times and not expect to find yourself in trouble.”

Clinton’s campaign did not respond to a request for comment from The Hill.