We'll see if this holds but assuming this is true, Hillary's negatives rising while Trump's decline may be 100% related to the email scandal. It appears that may be hurting her more than the press wants to admit. And it's something people can understand. First, being careless with Classified information while SOS and then asking people to make you CIC is a tough sell.
Secondly, people believe a crime was committed and that she "got away with it." This reinforces the belief that two sets of laws exist. One for people like Hillary and another for everyone else.
This raucous convention isn't going to help her situation, either