I think for many of her supporters - an indictment matters. They do not acknowledge that she did anything wrong here - this is just partisan politics attacking one of their own.
So, an indictment will be their first step to recovery - acknowledging that there is a problem.
Beyond that, I think people just would not want to deal with the hassle of going through the circus of a president going to trial, and/or another impeachment hearing. And nothing getting done on top of that. In a year, where the anti-establishment feelings are bubbling over, even she knows, deep down, that she can't win a general election under indictment.
I am of the belief that there will never be an actual indictment. If there is sufficient evidence to warrant an indictment, it will be a political decision to present that to Clinton, and agree to table the indictment (presumably with a full presidential pardon) in exchange for Clinton quietly (yeah right) stepping down from the nomination.
I don't like her, and I am quite certain she would be a lousy President, but I am fine with going down this path, where she is never in front of a judge/jury, and simply walks away - assuming there are facts sufficient to indict.