Question: why would the Ruskies need to buy Trump when they already own Killary?
You're a fool if you think they don't have the entire contents of Killy's private email server, much of which is certain to be excellent blackmail material.
Regardless, the source of the leak doesn't much matter; it doesn't detract from the simple fact that the DNC and its standard bearer are repugnant crooks that completely gamed the system.
Why did they bother with the charade of having "primary elections" at all, if not to intentionally deceive their electorate? Clearly the outcome was preordained.
Hedging their bets. Putin will decide who the POTUS is.