To expand a bit on why I don’t believe that low turnout was one of the major factors in Trump’s victory, it’s worth pointing out Trump’s record unpopularity among the general electorate in 2016 was worse than Clinton’s, so it’s not clear at all from the data (at least that I’ve seen and that you’ve presented) that Clinton was more affected by low turnout. After all, she received only marginally fewer votes than Obama did in 2012 — Trump simply improved on Romney’s performance in certain areas.
And in any case, it’s not totally correct to discuss raw vote tallies as a cause for Trump being elected president, given the relatively high margin by which he lost the popular vote to Hillary Clinton. What’s far more interesting is the swing of the upper midwest towards Trump, which in some places was quite high. Maybe a subtle form of white identity politics was at play here (certainly, that seemed to me to be an undertone of much of his rhetoric)? Maybe his rhetoric was uniquely effective at winning him the sympathy of the large group of people in that region of the US who suspect, not entirely incorrectly, that the economic centers of the US have shifted away from the heartlands and to the coasts and big cities? Maybe he managed to increase his support in the upper midwest by taking advantage of the fact that few Americans are sufficiently familiar with basic civics and sufficiently informed about current political discussions to be able to distinguish fact from fiction (which as we all know is crucial for the proper functioning of a democracy), to a much greater extent than any national level politician has done in the past, which he was able to do by taking advantage of people’s frustration with “the media”, i.e. cable news, which for many decades has shied away from reporting hard-hitting facts for fear of alienating its audience, and tended towards broadcasting bloviating pundits and hot-headed uninformed shouting matches, a skill which Trump, ironically enough, displayed repeatedly and shrewdly during the presidential campaign? Though I can only guess about the extent to which the tendency for cable news to replace fact-based with emotive ideology-based reporting gave rise to Trump, it’s undeniable that this phenomenon has been a staple of American political life, especially though not exclusively on the right and the radical right (see Sean Hannity, Rush Limbaugh, Alex Jones, Glenn Beck). This has been compounded by the rise of religion in politics, especially fundamentalist religion (see Jerry Falwell, Pat Robertson). This is, of course, a very incomplete list, but it should give you an inkling of some of the issues that lead to Trump’s win. To truly discuss them in detail would probably require a 900 page tome.