People being persuaded by one side of the argument via 'lies and deceit implemented by hackers with an agenda' has nothing to do with democracy being challenged.
In the end, your own personal vote matters in that you could have been "bombarded" with a certain narrative 99% of the way through the debates yet, in the voting booth, change your mind at the last moment to go against everything you were told, because we're allowed to do that. Human beings have that capability. You don't have to justify your voting decision to anyone. It's not required to have your vote be validated nor does it mean your vote means anything less than anyone elses who may have been more informed, nor should it mean their votes are discounted. THAT would be against democracy. Suggesting that there is an "evil, hidden force at work, manipulating the public with nasty messages designed to penetrate their minds to vote in the way they want them to" is outlandish.
My ONLY concern about hacking is if it directly affected the votes via changing them once they had been cast. i.e. fraud. If i've voted one way and hackers changed my vote to give the opposing opinion as it was being counted, then i'd have concerns. I don't care one jot if there are hackers manipulating the press, my facebook feed, I still have the capacity to ignore their message and make my own decision. Some people voted becase they believed a slogan on a bus, some people voted because they did more accurate research and some people voted the way they did because they went "meh, fuck it". Regardless, under our democratic system, all those votes are valid and are counted equally.
It's left up to the analysts to debate whether their votes were 'ethical', 'beneficial' or 'informed'. Doesn't matter to the vote count itself, nor should it. One person, one vote, how that vote is cast has nothing to do with anyone else other than the individual who casts it. All you can do is use your vote to challenge theirs.