As the boss wrote this morning, Democrats are mired in denial about the 2016 election. Since nothing is ever Hillary Clinton's fault (she's always the victim, don't you know) they need someone or something to blame for her spectacular implosion. They've tried to pin it on racism, sexism, bigotry, homophobia, voter fraud, and the FBI, all to no avail. Nothing seems to stick. So now they seem to have settled on "Russian hackers."
The theory is that Russia hacked the DNC, revealed information about Hillary Clinton, and that swayed the public's opinion. To put that argument another way, "Democrats believe their candidate would have won if only voters had been given less information about her." It would seem to me that, if you're arguing the leaks hurt Hillary because they were factual, you're not disproving the case that she was a horrible candidate, you're making it.