Trump vs. Harris: This glitch triggered a landslide victory

“It was right in my face, but I didn’t notice it at first,” the Northwestern University data scientist told this reporter by phone on Sunday. “I saw this huge increase in Harris’ support on July 31, but I didn’t connect it to Trump’s appearance at the National Association of Black Journalists convention that day. That event, not the debate, which only made things worse for Trump, marked the crucial turning point in the campaign.”

Miller’s election forecast relies not on polls but on the percentages for each candidates published on the betting site PredictIt. He considers PredictIt’s odds to be way more reliable than polls that reflect voter preferences which might be 4 to 5 days old. And because polls typically survey 500 to 1,500 likely voters, they contain plenty of statistical “noise” – hence the wide variability within the numbers published by the varied modelers.

PredictIt is probably the most liquid betting market, with a median of 37,000 bets per day, Miller said. And because each player has an $850 limit, no single bettor or group of high rollers can artificially inflate the percentages for one candidate or one other.

Trump led before the NABJ debacle

First, Miller’s model assumes that the percentages on PredictIt accurately reflect the chances of the voters’ votes. Simply put, a candidate who’s given a 55% probability of winning, or who’s rated at 55 cents on PredictIt, is prone to receive an identical share of all votes forged. Second, Miller shows that historically, the chances of the electoral vote exactly correspond to the share of the 538 electoral votes each candidate receives. He found that this relationship has remained extremely stable in every race since 1960.

Miller’s homepage, The virtual toutshows a chart showing the share of electoral votes leaning in favor of the Democrats, overlaid with the events which have significantly modified the percentages, and thus also the fluctuations within the projected election result across the 270 votes needed to win.

Between July 21—the day President Biden dropped out of the campaign and endorsed Harris—and July 27, her vote totals rose significantly, before remaining stagnant for 4 days in a row.

“She was still well behind the former president and it seemed as if her vote had stagnated,” Miller says.

But then, Miller said, got here an earthquake that might well turn right into a landslide victory for Harris by November. On July 31, on the NABJ’s annual colloquium, Trump falsely claimed that Harris had modified the best way she characterised her ethnicity, questioned her bi-racial background, and accused the vice chairman of “accidentally becoming black” and of Harris “now wanting to be known as black.”

Although the inflammatory comments sparked outrage within the press and amongst pundits, virtually nobody has called Trump’s NABJ interview the decisive turning point of the election. Miller points out that the PredictIt market went into turmoil that day as bettors switched en masse from Trump to Harris.

“On that last day of July, over 100,000 shares traded, three times the usual number,” he says. “Literally overnight, the election shifted from a Republican to a Democratic lean as Harris rose to over 270. Trump’s statements at the NABJ conference proved to be a complete disaster for his campaign. They had nothing to do with Harris’ actions. The enormous shift was entirely Trump’s doing.”

After the NABJ debacle, Trump partially closed the gap – then got here the talk

Miller’s chart shows that Harris’s vote share continued to rise over the subsequent two weeks, peaking just before the Democratic National Convention began. But the spectacle within the Windy City itself failed to supply any additional boost. By early September, her vote had fallen barely. And on September 6, news that Trump’s hush money trial can be delayed until after the election boosted his vote. The day before the talk, he was only barely behind.

“Although Harris was still leading at this point, the race was almost dead,” says Miller. “It’s notable that most of the jumps in Trump’s numbers came from good news about his legal problems.”

Then the talk in Philadelphia sent Harris’s polling predictions soaring. “That spike was the combined result of the debate and Taylor Swift’s support for Harris,” Miller says.

As of September 22, PredictIt prices suggest Harris’ possibilities of winning are 56.3%, while Trump’s likelihood is 43.7%. Those odds, Miller said, would result in a landslide victory for the vice chairman with 43 days to go.

“Big events can change everything, there are wars raging that could affect the outcome of the race, and candidates can make big mistakes,” he warns.

But straight away, he says, Harris is way ahead and the polls haven’t yet caught up with the large lead that’s prone to emerge – and that began to emerge the day Trump made those devastating comments to black journalists and squandered a lead that he was never capable of regain.