"This looks like Watergate on steroids," said Donald Trump about the controversy over Hillary Clinton's e-mails. But could she or anyone else actually face criminal charges?
It's an issue that won't go away, with a federal inquiry underway and members of Congress demanding answers. Here's where things stand:
What' is the FBI investigating?
Federal agents are looking at whether classified information was compromised. In sending the issue to the FBI, the inspectors general of the State Department and the intelligence community said federal law requires them "to refer potential compromises of national security information" to appropriate officials.
They acted after intelligence analysts said some e-mails publicly released from Clinton’s private server contained classified information.
One of the messages, dated April 2011 and forwarded by Clinton's close aide Huma Abedin, discussed deteriorating security conditions in Benghazi, noting that the U.S. ambassador was considering leaving and passing along reports from the U.S. military on the movements of Libyan government forces.
Another, dated November 2012, forwarded an e-mail about possible arrests in Benghazi after the attack on U.S. diplomats. Portions of that message were redacted before it was made public.
Congressional sources say those two e-mails led to concerns by the inspector general of the intelligence community, which ultimately prompted the referral to the FBI.
Though the two e-mails have been public since the spring, that aspect of the story was first reported by Fox News.
Both those e-mails originated in the unclassified State Department system, originally written by career department officials. One message was marked “SBU” — sensitive but unclassified. The other had no such markings.
Clinton says she didn't think any of the e-mails were classified.
"I did not send classified material, and I did not receive any material that was marked or designated classified, which is the way you know whether something is," she said Tuesday while campaigning in Las Vegas. But could she be charged with a crime?
Some Republicans have said it could be a case like the one against former General David Petraeus. He pleaded guilty to mishandling government secrets, admitting that he gave briefing books with classified material to his mistress, Paula Broadwell, who was writing a book about him.
Clinton supporters say that was very different. "You had someone who knew he was holding on to classified information, admitted on tape that he knew the information was classified, and then took it and turned it over to someone who was not authorized to view that information," says Matt Miller, a former Justice Department spokesman in the Obama administration.
But a former Republican attorney general, Michael Mukasey, says Clinton could be charged, just as Petreus was, with keeping classified material where it shouldn't be.
"The place in his case was his home. In her case it's her private e-mail server. So the question then becomes whether she was the one who caused it to be done and whether she knew that information on there was classified.”
Could others be charged with a crime?
Legal experts say that would require proof that they knew they were putting defense information into her unclassified server or that they were grossly negligent in doing so.
Criminal charges seem a long shot. Nearly all such cases involve espionage or leaks to the press, not e-mails from one government official to another.
The FBI insists that it's examining how the system worked — what went into the server and how it got there — and that no specific people are under investigation.
Faced with more questions Wednesday about the e-mails, the Clinton campaign said nothing that has come to light suggests that she has done anything improper.