In a letter contained in a court filing, the FBI finally confirmed what everyone in America already knows: they are investigating Hillary Clinton's use of a private email server.

Previously, when questioned about FBI interest in the controversey, the Bureau had simply stated that it couldn't comment about an ongoing investigation.  But in a letter dated February 2 and filed with a federal court in connection with an FOIA request, the FBI acknowledged their interest.

MSNBC:

Why say this at all, since it was widely known to be true?  Because in August in response to a judge’s direction, the State Department asked the FBI for information about what it was up to.  Sorry, the FBI said at the time, we can neither confirm nor deny the existence of any investigation.

Now, in a letter dated February 2 and filed in court Monday, the FBI’s general counsel, James Baker, notes that in public statements and congressional testimony, the FBI “has acknowledged generally that it is working on matters related to former Secretary Clinton’s use of a private email server.”

Baker says the FBI has not, however, “publicly acknowledged the specific focus, scope or potential targets of any such proceedings.” 

He ends the one-paragraph letter by saying that the FBI cannot say more “without adversely affecting on-going law enforcement efforts.”

The letter was filed in one of the Freedom of Information Act cases brought against the State Department over access to documents from Hillary Clinton’s time as secretary of state.  This one was filed by Judicial Watch.

It's hard to see how the FBI could be investigating Clinton's private server and not Clinton herself.  In that regard, it offers Bernie Sanders a unique opportunity to ask voters a question: do you really want to vote for a candidate who might be indicted for serious felonies down the road?

To date, Sanders has shown a reluctance to attack Hillary on her use of the private email server.  If he is truly a serious candidate for president, it's difficult to imagine him continuing this strategy.  Perhaps his surrogates will now go on the attack, raising the issue in voters' minds.

Will she be indicted?  There are calls for Attorney General Loretta Lynch to step aside and allow a special prosecutor to look into the case:

Already, top Republicans are calling for a special prosecutor to be brought in and evaluate the situation.

No. 2 Senate Republican John Cornyn (Texas) took to the floor of the Senate last week to call for a special counsel to be appointed “because of the conflict of interest by asking Attorney General Lynch to investigate and perhaps even prosecute somebody in the Obama administration.”

Senate Judiciary Committee Chairman Chuck Grassley (R-Iowa) agrees that Lynch ought to consider a special counsel, a representative said, to reassure the country that decisions are made “without regard to any political considerations.”

The Justice Department, however, has so far declined the request.

“This matter is being reviewed by career attorneys and investigators and does not meet the criteria for the appointment of a special prosecutor,” department spokeswoman Melanie Newman said in a statement.

Sanders and Clinton are expected to battle it out well into the spring.  At some point, the FBI will have to say whether Hillary herself is a target of the investigation.  The closer to reality an indictment becomes, the more the situation will weigh on her campaign, potentially dragging her down to defeat – even if she avoids prosecution.