I believe it will be difficult for Hillary Clinton to overcome the hurdles of the Benghazi incident as well as the illegalities of her maintaining a State Department email server in her home/office and unlawfully deleting a potion of those emails that were legally required to be stored in the National Archives, let alone her deficiencies during the Bill Clinton administration and her time as Senator. These are all serious issues and blatantly unlawful and even some felonious activities. Opponents may even bring up Whitewater and other scandals from decades past to add more to the list.

The Email Scanel Issues of legality, or a lack thereof:

• The Federal Records Act requires agencies hold onto official communications, including all work-related emails, and government employees cannot destroy or remove relevant records. - http://www.gpo.gov/fdsys/pkg/USCODE-2008-title44/pdf/USCODE-2008-title44-chap31-sec3101.pdf
• FOIA is designed to "improve public access to agency records and information," and those emails are public information if not determined to be state secrets, which they have not. Mrs. clinton does not ahve the authority to bdetermine them to be state secrets. - http://www.gpo.gov/fdsys/pkg/PLAW-104publ231/html/PLAW-104publ231.htm
• The NARA regulations dictate how records should be created and maintained. They stress that materials must be maintained "by the agency," that they should be "readily found" and that the records must "make possible a proper scrutiny by the Congress." - http://www.gpo.gov/fdsys/pkg/CFR-2012-title36-vol3/pdf/CFR-2012-title36-vol3-part1222.pdf
• Section 1924 of Title 18 has to do with deletion and retention of classified documents. "Knowingly" removing or housing classified information at an "unauthorized location" is subject to a fine or a year in prison. - http://www.gpo.gov/fdsys/pkg/USCODE-2009-title18/pdf/USCODE-2009-title18-partI-chap93-sec1924.pdf

Now, it will probably never be known what exactly was in those deleted emails, but we do know that she blatantly broke the law and by maintaining the private email server for government use and deleted those emails. We can surmise that she didnt want anyone reading them because of their content. Then we can assume they - or some of them - concerned the Benghazi incident. It's unknown whether or not she will be indicted, but you dont need an indictment to be considered political poison, because you have her blatantly breaking the law in so many ways. Then then there is her conflicting and combative testimony before Congress.

All that said, Elizabeth Warren has always stated that she will never run against Hillary Clinton, so I believe Elizabeth Warren's appearance on the political stage for presidential candidacy for the 2016 race will be the determining factor for the DNC's decision whether or not they deem Hillary Clinton as electable in 2016, so keep an eye on Elizabeth Warren to understand how the DNC views Hillary's electabiliy... that is, if the DNC considers Hillary unelectable and can convince Warren to run. Warren's feminist and female-centric ties with Clinton may be stronger than DNC pressure. I am really not sure, but you can be sure that if Warren runs, Hillary is extremely weak.