Both DNC and also the Clinton Campaign (Campaign Chairman Podesta). Podesta was hacked by pfishing which most users < 30 knows to avoid. Tells me Podesta had no geek friends.
https://www.vox.com/policy-and-politics/2016/10/28/13456368/...
"Seemingly skeptical (and rightfully so), Podesta forwarded the email to his chief of staff, who then passed along the email to the campaign’s IT team. This is where things go so painfully wrong: The campaign’s IT team incorrectly identified the email phishing for Podesta’s password as legitimate, instructing him to change his password."
The phishing email claims to be from from Google support, and tells the user:
> CHANGE PASSWORD: <https://bit.ly/[deleted]>
That should be enough red flags. Also, the bitly address expands to one in the domain, myaccount.google.com-securitysettingpage.tk
If you visit the stats page for that bitly link by adding a + to the end, you'll find that it was visited exactly twice, both visits at the right time for the hack, and you'll find that the Wikileaks data cuts off soon after the hack, probably when they set up 2FA as suggested. While that doesn't technically prove that they're related, it's better evidence than we have for any other theories.
Sources:
Bitly stats page: https://bitly.com/1PibSU0+
Phishing email: https://wikileaks.org/podesta-emails/emailid/34899
This is my source: https://motherboard.vice.com/en_us/article/how-hackers-broke...
Also, I learned recently that Clinton didn't know how to use a personal computer. Nobody on her staff could take the time to teach her the basics.
People basically treat their laptops as glorified thin clients nowadays.