Via TIME magazine, this article, unlike many in the media, doesn't seem to have been written by a Clinton staffer:
The questions about Benghazi appear to have taken a toll on Clinton. Her trustworthiness, which has also been battered by a debate over the proper handling of her private email accounts, has sunk significantly among independents and even slightly among some Democrats, polls show. “Hillary is a liar. Benghazi is a big problem,” said Sean Adkins, a Democrat and native of Waterloo, Iowa who supports Bernie Sanders. One of the most pointed questions Clinton faced during a CNN town hall last week in Iowa came from a student who said, “I’ve heard from quite a few people my age that they think you’re dishonest.” An ABC/Washington Post poll released last month shows that while Clinton is the favorite of most Democrats by a significant margin, Democrats think Sanders is more honest by a margin of 48% to 36%.
Clinton, for her part, has said she will stand up to partisan attacks on her record. “Why is this being used as a great political issue? I really regret it is,” Clinton said at Henniker. She added that the investigations into Benghazi have been exhaustive, compared with other crises like the September 11th attacks. “I regret that four brave Americans whose lives have been lost serving our country has been put in the middle of what is a very political effort. I just think it’s wrong and I don’t think it should continue.”
Why indeed? Clinton is running for president on three issues a) she allegedly had sex with Bill Clinton, b) she allegedly has a vagina, and c) she was Secretary of State. Benghazi is not so much a political issue because of the attack and the actual deaths of US citizens there but because of the actions of Hillary Clinton and her State Department. Regardless of the merits of running an arms smuggling operation out of the US consulate, what makes it a political issue was Clinton's lying to the American people for over a week after the attack, blaming it on an internet video, when she told her family it was al-Qaeda related right away. What makes it a political issue is Clinton's statement at Dover AFB when those men's bodies came home. What makes it a political issue is Hillary Clinton lying to the families of the fallen men about how their deaths came to be:
and capping this off by calling the families liars.