As a victory for Hillary Clinton becomes more likely, and a big victory more probable, observers are beginning to wonder if Donald Trump is refuting the common political science principle that at the presidential level “fundamentals” matter more than candidates or campaigns. I discussed this possibility at New York:

Donald Trump’s campaign is throwing political scientists (along with journalists, Republican politicians, and many voters) for something of a loop.

This problem began back during the primaries with Trump’s success in the teeth of near-universal opposition from Republican elected officials and many other ideological and constituency-group elites with influence over the GOP. That was not really supposed to happen, according to the reigning political science wisdom, as expressed in the highly influential 2008 book, The Party Decides, which suggested early elected-official endorsements were a much better guide to a reliable prediction of who would win the nomination contest than early polls.

After Donald Trump won the nomination despite badly losing the endorsement contest, Andrew Prokop of Vox offered a good retroactive qualifier for the academic consensus:

“When The Party Decides was written, it offered valuable pushback against the conventional wisdom that parties had lost all their influence on the nomination process. And its focus on endorsements is a helpful alternative to early polls that have frequently been wrong. But in the time since, ‘the party decides’ has become the new conventional wisdom among some wonky pundits — despite the small number of modern contests and the many messy exceptions, especially in recent years.”

And so, future editions of The Party Decides will have to contextualize what happened this year, which will probably reduce the authors’ self-confidence about predicting future contests.

But Trump is also in the process of disrupting certain political-science theories about general elections: not by winning, as he did during the primaries, but by losing more soundly than anyone expected. Hillary Clinton currently leads Donald Trump by six points in RealClearPolitics’ polling averages, and a lot of observers think her lead could balloon because of the dynamics of the final debate and her significant advantages in paid advertising, voter targeting, and get-out-the-vote investments.

If Clinton does win by six or more points, it will cast some doubt on political scientists’ prediction models, many of which depend on data points recorded much earlier in the cycle (i.e., they won’t change). Here’s how Larry Sabato’s Crystal Ball summarized the academic-prediction literature in mid-September:

“Averaging all the forecasts together shows a two-party vote of Clinton 50.5% and Trump 49.5%. Obviously, that’s very close, and taken together these models produced a very similar prediction in 2012 (Obama 50.2%, Romney 49.8%). That undersold Obama, who won with 52.0% of the two-party vote.”

The forecasts could very easily “undersell” Clinton by quite a bit more.

As Nate Silver suggests, that will have some troubling implications for political scientists who tend to believe “fundamentals” — especially economic indicators — matter a lot more than the noisy stuff that happens in the political world:

“If Clinton wins by a clear margin, it will help to resolve a longstanding debate among political scientists and historians, since it will suggest that campaigns and candidates do matter and that elections aren’t always determined by economic conditions, which would predict a much closer outcome than the one we’re likely to see. Furthermore, Clinton’s win will have come by rather conventional means. Her big surges in the polls came following the conventions and the debates. She got the largest convention bounce of any candidate since at least 2000, and she won the debates by a clearer margin than any previous candidate in the six elections in which there were three debates that CNN polled.”

It is possible, however, that Trump will ultimately be regarded as an exception that proves various rules rather than a newly normal phenomenon. Here’s how political scientist Alan Abramowitz, whose own model predicted a Trump victory, contextualized this election:

“As Abramowitz explains it, the assumptions upon which the model is built are unsound: ‘First, that both major parties will nominate mainstream candidates capable of unifying their parties and, second, that the candidates will conduct equally effective campaigns so that the overall outcome will closely reflect the ‘fundamentals’ incorporated in the model.'”

Trump is nothing if not outside the mainstream. He clearly has not unified his party. And his campaign has ignored many of the minimum expectations for competent national political campaigns.

In other words, it’s possible we may never see the likes of Trump again — or so hope many political scientists.