This writer has been filing regular updates on the outlook for the presidential election based on projections by renowned data scientist Thomas Miller, a professor at Northwestern University. Miller maintains that his model guided by political betting data is a much better forecaster than following the individual polls.
Miller stresses that his approach is based on results of presidential elections over sixty years.
I became convinced that Miller’s got a better system while following his framework and predictions during the 2020 election cycle. He called the presidential race for Biden within 12 electoral votes, and in the Georgia senatorial runoffs that followed, posited that Democrats Raphael Warnock and Jon Ossoff would both win when the polls still showed them trailing their GOP opponents by substantial margins.
On the Harris-Trump race, I’ve posted three stories between September 18 and October 3, and in all of them, Miller’s methodology showed Harris holding a big lead, while the polls displayed a dead heat, and the media almost invariably characterized the contest as too close to call. In fact, the earliest piece stated that by Miller’s metrics, the vice-president could be headed for a landslide approaching President Johnson’s blowout victory in 1964. Even in the October 3 update, Harris—as of the previous day—was leading the former president by a a big bulge of 66 electoral votes, 302 to 236.
In the past week, the contest’s taken still another abrupt turn—this time in Trump’s favor
In a battle that already charts like the craziest of rides on the waviest of rollercoasters, Donald Trump over the week through midday on October 9 has staged a sharp comeback. To Miller, that’s proved something of a surprise, since the in the twenty days or so following the presidential debate, the race had seemingly entered a steady state where Harris consistently held the lead. But as of midnight on October 8, the Miller system gives a tiny edge to Trump, 270 to 268 for Harris. “This is the first time in history that a race has gone from a tossup to a landslide for one party then to a tossup then to near landslide for the other party, then back to a tossup,” Miller told Fortune. “The dynamic of this election is that after one candidate jumps way out in front, the race always works its way back to even. That’s where it stands now. I follow this minute by minute, and the results keep toggling back and forth around the 270 electoral votes needed to win.”
It’s important to briefly review the Miller model that worked so well in 2020. It’s governed by two ruling principles. The first relies on the probabilities expressed by bettors who’ll reap big gains if the candidate they’re wagering will win, not the ones they plan to vote for, prevails on November 5. To get those odds, Miller uses the prices posted on the most established political betting site, PredictIT, which on average trades a gigantic 35,000 shares a day bought or sold on the two candidates. Miller eliminates the votes for third party contenders, and makes the Trump and Harris prices equivalent to 100% of the total.
He then deploys his methodology to translate the probabilities into popular vote shares for each candidate. That task requires a number of adjustments. For example, a 50% share on PredictIT for Trump equates to less than 50% of the likely popular vote for the GOP ticket, in part because the wagerers are mainly men, and often regular sports gamblers, who lean Republican. On the other hand, a Republican ticket can win at well under half the popular vote, another factor Miller’s calibrated in his numbers-crunching.
The second ruling guideline: The projected popular vote percentages closely track the share of electoral votes each candidate receives. That’s the data scientist’s takeaway from studying every election since 1960. In the last few days, the PredictIT odds have narrowed from favoring Harris by several points to virtually even, accounting for the electoral lead that’s now see-sawing from one candidate to the other, within a narrow bands of a few electoral votes (EVs).
Following the careening course is an exercise in electoral whiplash
On his homepage The Virtual Tout, Miller posts a graph showing the Democrat EV share at the close of each day, overlaid by big events that appear to have moved voters. The graph resembles a giant “S” laid on its side. In early June, a Biden-Trump face-off looked like an even match. That was the first “tossup” moment. Following their debate on June 27, Trump took a huge lead, and by the time of the Republican convention in mid-July, Trump had a commanding total of well over 300 EVs. That was the “First Landslide” phase, and the only one for Trump. The Republican standard-bearer maintained a double-digit EV lead until his disastrous appearance before the National Association of Black Journalists on July 31, where he falsely claimed that Harris misled voters about her race.
That day, the Democrats took the lead for the first time. But Trump bounced back fast, almost leveling the count by August 5. That’s the “Second Tossup” point. The next day, Harris secured the nomination and named Tim Walz as her running mate. Biden’s withdrawal gave the Dems a big boost, and sent Harris climbing; she reached a summit of just over 350 electoral votes on August 11. That milestone marked the apex of the “Second Landslide” span, this time tagging Harris as the big victor just a month after Trump looked like an easy winner.
Once again, Trump closed the gap, getting within seven EVs of Harris on September 9, the day before the debate. That’s “Third Tossup” point. Famously, Trump’s disappointing performance onstage in Philadelphia sent loads of EVs into the Harris column. This time, the uptrend peaked on September 20 at 337 Harris votes to Trump’s 201. The chart had careened to the “Third Landslide” zone, the second time in six weeks that Harris looked headed for a walkaway.
In late September, the gulf gradually narrowed. Miller believes that J.D. Vance did a bit better than Walz in their October 1 debate. But Vance’s good performance, he says, did virtually nothing to improve Trump’s chances. Two days later, Harris still held a significant edge of 58 EVs at 298 to 240. Trump’s big surge started on October 4. In the four days that followed, he vaulted to 270 and into the tiniest of leads, while Harris dropped from by 30 EVs to 268.
Miller sees a deadlock till November 5, not a continued movement toward Trump
I ask Miller if he sees a wave building for Trump, given the momentum he’s shown in the past few days. “I don’t think so,” he replies. “Trump’s still playing to his base. I haven’t seen him changing his pitch to reach out to more voters like a normal politician.” So what accounts to the sudden jump in the GOP numbers? “It may be because of fears of widespread warfare in the Middle East, and that American troops will join the conflict,” he notes. “The Biden regime is pursuing a traditional foreign policy of supporting allies militarily, leading to the view that could happen. Trump is more of an isolationist, and that appeals to a lot of people who think of Afghanistan and Iraq and say, ‘Why are we trying to do this? Why get involved in foreign wars?’ A lot of people across the spectrum are not interested in our going to war.”
The pattern of huge surges that keep deflating, bringing the race back again and again into even balance, symbolizes America’s current predicament. “We’re an incredibly divided nation,” says Miller. “The most likely trend over the next 26 days to November 5 is that the forecast keeps going back to a tossup. The next month will be a crazy time.”
