This maybe one reason for Hillary Clinton's evidence destruction

Gawker:

Starting weeks before Islamic militants attacked the U.S. diplomatic outpost in Benghazi, Libya, longtime Clinton family confidante Sidney Blumenthal supplied intelligence to then Secretary of State Hillary Clinton gathered by a secret network that included a former CIA clandestine service officer, according to hacked emails from Blumenthal's account.

The emails, which were posted on the internet in 2013, also show that Blumenthal and another close Clinton associate discussed contracting with a retired Army special operations commander to put operatives on the ground near the Libya-Tunisia border while Libya's civil war raged in 2011.

Blumenthal's emails to Clinton, which were directed to her private email account, include at least a dozen detailed reports on events on the deteriorating political and security climate in Libya as well as events in other nations. They came to light after a hacker broke into Blumenthal's account and have taken on new significance in light of the disclosure that she conducted State Department and personal business exclusively over an email server that she controlled and kept secret from State Department officials and which only recently was discovered by congressional investigators.
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The contents of that account are now being sought by a congressional inquiry into the Benghazi attacks. Clinton has handed over more than 30,000 pages of her emails to the State Department, after unilaterally deciding which ones involved government business; the State Department has so far handed almost 900 pages of those over to the committee. A Clinton spokesman told Gawker and ProPublica (which are collaborating on this story) that she has turned over all the emails Blumenthal sent to Hillary.

The dispatches from Blumenthal to Clinton's private email address were posted online after Blumenthal's account was hacked in 2013 by Romanian hacker Marcel-Lehel Lazar, who went by the name Guccifer. Lazar also broke into accounts belonging to George W. Bush's sister, Colin Powell, and others. He's now serving a seven-year sentence in his home country and was charged in a U.S. indictment last year.
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There is much more.

If these emails were not in those produced by Clinton to the State Department, it could enhance a case against her for destruction of evidence, assuming they are shown to be valid.  Their very existence would demonstrate an attempt to hide evidence from Congress and thwart the FOIA process.

Ed Morrissey has more on the story including an interview of chuck Todd by Hugh Hewitt, that touches on the Blumenthal link.

This will probably further damages her Presidential ambitions.  She wants a smiley campaign about electing a woman, and it is about to become about her obstruction of a Congressional inquiry into her actions as Secretary of State.