The thing with the presser now, though, is that you give in to what Trump's saying and what the media is bitching about. I'm not quite sure why they didn't do them, to be honest.
I think the debate has a lot to do with it.
Trump may try to gloat about putting pressure on her to do a presser, but I don't think that'll ring louder than the fact that she's doing one at all. Plus, it's in her best interest to make the first debate as stark a contrast as possible. She should do everything she can to take all the bite out of her scandals before the debates. Do a press conference, answer questions about emails and the Foundation. Take it off the table.