In broad strokes, the national-level story of the United States 2016 Presidential election could be described as that the rough trend continued.
There was a swing up between the mid 90s and the mid 00s. The Democratic and Republican percentages of the voting age population (VAP) both increased in 2000 and 2004, with a much bigger Republican increase in 2000.
Then there was a transition in 2008. That year, the Democrats had a much bigger increase equivalent to the Republican jump of 2000. Meanwhile, the Republican turnout began sliding down.
And now we're in a swing down in the 10s. The Democratic and Republican percentages of the voting age population both decreased in 2012 and 2016.
Where will we go from here? For both parties, the percentage of the VAP in 2016 was still up from what either party saw in 1996 and 2000. Considering the past two decades on average, we can't really say there was low turnout in 2016; just not quite as high as the peaks. Both candidates this year got a higher percentage of the potential vote -- more support -- than even the winning candidates from 16 and 20 years ago. We'd have to go back to 1984 to find a higher percentage of the VAP turning up for the two major parties; and that was the only higher year between 1980 and 2000. Based on the trend of the last 10 elections, we're likely only approaching the valley and barring some particular phenomenon drawing more people out to vote we'll likely see yet another decline in overall turnout next Presidential election.
If there's one thing we can say from the overall national trend, it's that the narrative of unenthused voters doesn't really fit. We've heard claims that voters were particularly disinterested in these candidates. Yet what drop there was this year was only in keeping with the direction of the past few elections. The turnout / VAP in 2016 remained over the average for the last 10 elections.
There also quite clearly was no national surge whatsoever toward the Republican party. On the contrary, the Republican specific turnout was yet again down slightly, just like in the previous election. In fact, this year's Republican turnout brought it low enough at 24.87% to be below the 25.47% average Republican turnout for the last 10 elections.
Democratic turnout also was only down this year by about the same degree it was down the previous Presidential election. And that was only returning it towards the rough trend, smoothing out from previous big gains. The 2016 Democratic turnout of 25.75% remained slightly above the 24.92% they've seen for the last 10 elections.
By and large, the nation continued a return towards trend. The Republican party dipped slightly below their average; and the Democratic party remaining slightly above. There may have been changes in the character of each party's support, such as the widely reported gains among the less educated for Republicans and among the more educated for Democrats. But these qualitative fluctuations did not budge the totals from the previous quantitative heading nationally.
If there's a major story specific to this 2016 Presidential election that differs from the typical trend of the previous years, it would have to be at the state-by-state level. It isn't just that a few states decided the election in the electoral college; it's also that what happened in those particular states and the states that went the other way from them would together have to be the entire story of how this election might differ from the norm in voting.
* Popular vote totals used for the above analysis were derived from Dave Leip's Atlas of U.S. Presidential Elections as of 11/28/2016.