The scandal around Hillary Clinton's use of a personal email account to conduct State Department business doesn't appear to have yet had a significant effect on her chances of becoming the Democratic party's 2016 presidential nominee, perhaps because up to this point it's been more about the violation of abstract principles than about specific unsavory acts. It's been about what Clinton could be hiding rather than what she's actually done.
That might no longer be the case. In 2013, a number of emails written to Hillary Clinton by D.C. operative Sidney Blumenthal were leaked online, and in recent days Gawker and ProPublica have been reexamining those emails in light of the clintonemail.com controversy. A piece published Monday by Gawker's Sam Biddle quotes legal experts who say that Blumenthal may have violated the Foreign Agents Registration Act because he emailed Clinton on behalf of a foreign entity—specifically, on behalf of a Putin-friendly politican named Bidzina Ivanishvili who later became the prime minister of Georgia—even though Blumenthal hadn't notified the U.S. government that he was working on Ivanishvili's behalf. (The Foreign Agents Registration Act "requires persons acting as agents of foreign principals in a political or quasi-political capacity to make periodic public disclosure of their relationship with the foreign principal.")
Hillary Clinton isn't accused of doing anything illegal in the Gawker stories. And Blumenthal's advocacy appears to have been pretty tame, consisting of passing on the statements of a third individual who, it was acknowledged openly, worked for Ivanishvili. But the White House, as Gawker notes, had rejected Clinton's efforts to hire Blumenthal in an official capacity. So you have the Secretary of State using an off-books email account to discuss national policy with someone who wasn't a government employee, was known to be disliked by the president's staff, and who might have been violating an actual law by participating in the conversation. That's probably not something Clinton is going to brag about in campaign commercials. It's also exactly the kind of foreign entanglement that critics have warned she is susceptible to—of being unduly influenced by financial connections, via the Clinton Foundation, to foreign interests. Blumenthal is a longtime Clinton-family ally and appears to have described himself as an adviser to the Clinton Foundation on more than one occasion.
This could become an even stickier situation when the private emails Clinton handed over to the State Department are finally released. Clinton has so far asked the public to take her at her word that she gave State every private email that was work-related. So she'd better hope that her emails with Blumenthal about Georgia were included in that dump, or else she'll have walked into an actual smoking-gun example of having apparently used the private account to hide her involvement in dubious activities.
Now, given that the existence of Clinton-Blumenthal correspondence has actually been public knowledge since 2013, her camp definitely should have made sure to turn those emails over. But Clinton's handling of the private-email issue has not exactly been guided by thorough reasoning. At this point, who would be surprised if Hillary Clinton stepped into trouble by not being forthcoming enough?