Hillary should have won it in 2008. 2004 was too soon and she was too damaged of a political figure after Benghazi and the e-mail controversy.
You make the mistake of thinking people didn't trust/like Hillary in 2016 because of her "e-mails" or "Benghazi," lol. They didn't like her because they felt in their hearts that she was an over-ambitious harpy. The faux scandals gave them something to latch onto publicly that could seemingly legitimize their position. But if it couldn't be Benghazi or e-mails, it would've just been something else. There would have been a slew of other bullsh-t in 2004 not named e-mails but still equally as potent. And that's because the trajectory of the e-mail story was more a symptom of her being disliked than an actual cause.