Given that John Podesta's email password was p@ssword, I don't think it's reasonable to assume without a shadow of a doubt that a sophisticated Russian government hacking operation was the one that ended up putting it in the hands of Wikileaks.
I think one major development in the 2016 election was the 9/11 incident.
Much of the mainstream news media in America participated in a news cycle of essentially propaganda during the weeks leading up to 9/11 of last year. Candidate Clinton fainted (initially due to "overheating") on one of the most pleasant days of the year, (and later, pneumonia). Prior to this, rumors of her ill health were leaked by someone or the other, which then became more apparent with coughing at events and other questionable incidents. Like some sort of automated defense mechanism, all of this received a very strong, almost religious defense from much of the mainstream media and the late night talk show circuit, culminating in the candidate making an appearance on the Jimmy Kimmel show herself, to participate in a gag in which she opens a pickle jar, as if to dismiss the entire thing as a made up conspiracy.
Some links for emphasis on how bad this was:
MSNBC: http://www.msnbc.com/rachel-maddow-show/trump-allies-push-co...
CNN (before): http://edition.cnn.com/2016/08/22/politics/hillary-clinton-h...
CNN (after - doubling down): http://edition.cnn.com/2016/09/13/politics/hillary-clinton-h...
Washington Post (before): https://www.washingtonpost.com/news/the-fix/wp/2016/09/06/th...
Washington Post (after), same author: https://www.washingtonpost.com/news/the-fix/wp/2016/09/11/hi...
Google Search autocomplete: http://insider.foxnews.com/2016/08/28/google-censoring-searc...
Stephen Colbert: https://www.businessinsider.in/Stephen-Colbert-investigates-...
The Guardian: https://www.theguardian.com/us-news/2016/aug/26/hillary-clin...
Esquire: http://www.esquire.com/news-politics/videos/a47964/karl-rove...
Vox: https://www.vox.com/2016/8/18/12505078/hillary-clinton-healt...
BBC: http://www.bbc.com/news/election-us-2016-37090082
Politico: https://www.politico.com/magazine/story/2016/08/donald-trump...
In isolation, of course, this can be dismissed with a lot of different explanations, but the John Podesta emails highlighted the inappropriate relationship that many journalists seemed to have with members of the campaign. This is further coupled with the fact that all of the polling done by these groups and their affiliates showed an almost demoralizing level of support for President Trump. Heck, Chris Cuomo on CNN went ahead and told the viewers point blank that it was illegal to read Wikileaks and that it is "different for the media", so "everything you learn about this, you're getting from us".
It has been long known that Fox News leans heavily to the right and will almost always present stories with a perspective that is favorable to conservatives in government. This is pretty much universally accepted without debate. In 2016, however, much like Fox, the entirety of the mainstream media had effectively chosen a side in the election.
In my opinion, before blame can be cast on foreign governments, who are more than happy to engage in this kind of thing, since it is in their interests, it may perhaps be more prudent to raise some serious questions about how America's own news media is more than happy to push a particular agenda until is becomes untenable to do so in light of hard evidence, as was seen in the case of the 9/11 incident. This principly poses the exact same threat to democracy, with the exception that rather than serving the interest of a foreign government, it is serving the interests of the shareholders of the respective parent organizations, who may very well end up being foreign nationals with close ties to their respective governments.
The voter can choose to vote for a candidate based on any arbitrary reason. It is being assumed that most voters are reasonable people and will keep themselves informed by watching Presidential debates and keeping themselves abreast of the candidates' various policy positions from the news media. What the news media also seems to provide these days is opinion, in a subtle way that says if you belong to "X, Y, Z" category or circumstances, it's in your interests to vote for this candidate and not the other. In the case of some issues, you will see the exact opposite recommendation. For example Fox viewers right now are being told that the President's tax cuts will lower their taxes. CNN and MSNBC viewers are being told that the tax cuts are primarily for the wealthy. On the very same issue, the President is painted favorably and unfavorably for the same category of people on the same issue, with the rhetoric held up by convenient facts. In some such cases both are half-true, in some cases only one is true.
If the voting public's faith in their own news media is constantly eroded by this sort of thing, they will naturally seek out new sources of information that claim to be unbiased. These will include Wikileaks - which only publishes primary source information, but may do so selectively, in theory. This breeds the perfect circumstances for foreign governments to invest in alternative media in the form of YouTube shows and other internet-based news agencies, or facebook pages, advertisements, email campaigns, etc. If the public trusted the mainstream media, this would not really be a problem, so before anything else, I believe the blame rests with them first and foremost.