from The City Journal, Trump and the American Divide by Victor Davis Hanson:
Trump’s election underscored two other liberal miscalculations. First, Obama’s progressive agenda and cultural elitism prevailed not because of their ideological merits, as liberals believed, but because of his great appeal to urban minorities in 2008 and 2012, who voted in solidarity for the youthful first African-American president in numbers never seen before. That fealty wasn’t automatically transferable to liberal white candidates, including the multimillionaire 69-year-old Hillary Clinton. Obama had previously lost most of America’s red counties, but not by enough to keep him from winning two presidential elections, with sizable urban populations in Wisconsin, Michigan, Ohio, and Pennsylvania turning out to vote for the most left-wing presidential candidate since George McGovern.
Second, rural America hadn’t fully raised its electoral head in anger in 2008 and 2012 because it didn’t see the Republican antidotes to Obama’s progressive internationalism as much better than the original malady. Socially moderate establishmentarians like the open-borders-supporting John McCain or wealthy businessman Mitt Romney didn’t resonate with the spirit of rural America—at least not enough to persuade millions to come to the polls instead of sitting the elections out. Trump connected with these rural voters with far greater success than liberals anticipated. Urban minorities failed in 2016 to vote en bloc, in their Obama-level numbers; and rural Americans, enthused by Trump, increased their turnout, so that even a shrinking American countryside still had enough clout to win.
Obama won with fewer and fewer counties and electoral votes. Hillary’s loss was not revolutionary, but a continuation of Democrat deterioration that was still visible, if ignored, in Obama’s thin victories. In 2012 Obama won withe the fewest number of counties ever- 693 vs 2420. Hillary lost with 489 vs 2623. By comparison Bill Clinton won in 1996 with 1526 vs 1587 and by a similar split in 1992.