The 2016 US presidential election has been unprecedented in several ways. For starters, seasoned psephologists were surprised by Donald Trump's success in the Republican primaries.
And while the "fundamentals" of the election would suggest the Republicans would have a significant edge - due to tepid economic growth and an incumbent Democratic president - even one of the key proponents of this model doubts its applicability this year.
The reason for this doubt is that Trump is an unconventional candidate who has eschewed normal campaign practices such as setting up field offices, building up campaign staff, fundraising, and spending on TV advertisements.
Trump's campaign has been built upon controversial statements that have kept his name in the news. This strategy served him well during the primaries, where he received nearly US$3 billion in free coverage.
Any one of Trump's major gaffes would have likely been fatal for other campaigns. But he has proven uniquely resilient. Why?
Trump and populism
The narrative the Trump campaign has played during the continual turmoil and controversy that has surrounded him is that the elites who have abandoned him or disagree with him are all part of the establishment he seeks to destroy. This is a populist appeal that resonates with a large portion of the population who feel their voices have not been heard.
The leader is central to the idea of populism. It is the leader who will emancipate the "people" on their behalf, unshackling them from the ills, constraints, and indignities imposed upon them by a corrupt and indifferent elite.
Populism has been a part of American politics from its inception. The Anti-Federalists were a populist response to the push for the Constitution and the strong national government it created.
But, as Alexis de Tocqueville observed, Americans have been able to keep populism at bay and avoid the emergence of democratic despotism to the extent that they resist reliance on strong authority figures to emancipate them. They rely more on themselves and their democratic capacities to work together to affect change in some aspect of political life.
This is the same contrast Barack Obama drew during his speech at this year's Democratic National Convention between his view of America and the narrative developed by the Trump campaign.
A slow-moving trainwreck?
Many Republicans are now abandoning Trump following signs his campaign may be coming off the rails completely. The release of a video in which Trump describes himself as engaging in sexual assault led to scores of Republicans, including Speaker of the House Paul Ryan, abandoning him.
However, despite early concerns, they had dutifully fallen in line endorsing him between the primaries and the convention.
One of America's most-respected journalists, CBS' Bob Schieffer, described Trump's handling of himself in the second debate and particularly his threat to jail his opponent as "disgraceful" and beneath the dignity of the office he seeks.
Yet polling reveals 2016 is one of the most stable races in modern times. The reason for this appears to be growing partisanship. There has been a significant uptick in this since the 1990s.
Although there has been a consistent story about the level of undecideds and the level of support for third parties in this election, Democrat Hillary Clinton has retained a consistent lead since June 2016.
Not going away
In many ways, the populist vein that Trump has tapped into won't go away.
With a two-term Democratic president in the White House now, pundits have noted that 2016 is a "change election" whereby there is widespread fatigue for the incumbent party and demands for change, which has made the populist message resonate with so many. This has so far sustained Trump's campaign where others might have failed.
But it does not end there. If retweeting is a measure of Trump's support on Twitter, he does not have fair-weather fans. Rather, they are in for the long haul.
Consider the comparison between Trump and Clinton's average tweet metrics in relation to the margin of Clinton's polling lead. As Trump does worse in the polls, his retweets go up - whereas there is no statistically significant relationship between Clinton's retweets and her polling margin.
The conditions that made the Trump campaign possible will persist as long as there is a belief that governments are run by a corrupt and indifferent elite. It is a caution for whoever wins the White House that they will have to find new ways to connect with ordinary citizens.