The Justice Department is among the agencies that have reportedly opened inquiries into the handling of classified information on the server.

The email scandal first bubbled up last March, when the New York Times reported that Clinton had exclusively used a personal email account to conduct government business as secretary of state. Her aides took no actions to have her personal emails preserved on department servers at the time, as required by the Federal Records Act.

Later, an inspector general's report said classified information had been circulated through the server. It is illegal for someone to “knowingly” receive a classified document or briefing and then turn around and send along that info in an unclassified email, but the report did not specify whether Clinton sent or received the information.

Clinton said at the debate, as she has many times, that she never sent or received emails marked classified at the time.

Clinton has said she was not trying to hide anything, but merely set up the server for convenience's sake. However, her team said that the server was later wiped clean. They have since agreed to turn over the server to the Justice Department, and emails are being recovered.

According to one CNN survey, 63% of self-described independents and 30% of Democrats said Clinton did something wrong by using a private email account and server.

Rob covers business, economics and the environment for Fusion. He previously worked at Business Insider. He grew up in Chicago.