STONY BROOK, NEW YORK
FEBRUARY 26, 2016
A professor of political science at Stony Brook University has forecasted that Donald Trump has a minimum 97 percent chance of winning the general election as the Republican nominee.
Professor Helmut Norpoth’s forecast presentation took place Monday evening in the SUNY Global Center in Manhattan, which was organized by the Stony Brook Alumni Association.
Norpoth created a statistical model of presidential elections that uses a candidate’s performance in their party’s primary and patterns in the electoral cycle as predictors of the presidential vote in the general election.
Donald Trump has a 97 percent chance of defeating Hillary Clinton and a 99 percent chance of defeating Bernie Sanders in the general election, according to Norpoth’s formula.
“The bottom line is that the primary model, using also the cyclical movement, makes it almost certain that Donald Trump will be the next president,” Norpoth said, “if he’s a nominee of the [Republican] party.”
Norpoth’s primary model works for every presidential election since 1912, with the notable exception of the 1960 election. These results give the model an accuracy of 96.1 percent.
Norpoth began the presentation with an introduction of the potential matchups in the general election, including a hypothetical Sanders vs. Trump general election.
“When I started out with this kind of display a few months ago, I thought it was sort of a joke.” Norpoth said referring to Trump and Sanders, as many alumni in the audience laughed. “Well, I’ll tell you right now, it ain’t a joke anymore.”
As the presentation continued, laughter turned to silence as Norpoth forecasted a 61 percent chance of a Republican win in the general election.
This forecast was made using the electoral cycle model, which studies a pattern of voting in the presidential election that makes it less likely for an incumbent party to hold the presidency after two terms in office. The model does not assume who would be the party nominees or the conditions of the country at the time.
“You think ‘This is crazy. How can anything come up with something like that?’ ” Norpoth said “But that’s exactly the kind of equation I used to predict Bill Clinton winning in ‘96, that I used to predict that George Bush would win in 2004, and, as you remember four years ago, that Obama would win in 2012.”
Norpoth then added data from the New Hampshire and South Carolina primaries to narrow down the forecast to specific candidates. As he brought up the first slide with matchup results, the silence was broken by muttering from the audience.
“Trump beats Hillary 54.7 percent to 45.3 percent [of the popular vote]. This is almost too much to believe.” Norpoth said, with a few members of the audience laughing nervously. “The probability of that [outcome] is almost complete certainty, 97 percent. It’s almost ‘Take it to the bank.’ ”
The primary model predicts a Trump victory with such certainty due to Trump’s relatively high success in the Republican primaries, Norpoth said. Clinton, in comparison, is in an essential tie with Sanders in the Democratic primaries. As a result, Sanders would also lose to Trump in a similar landslide if Sanders were to be the Democratic nominee, Norpoth said.
In contrast, Norpoth forecasted that a hypothetical presidential race with Ted Cruz or Marco Rubio on the Republican ticket would be a much closer race. The results showed Clinton with a 55 percent chance of winning the race against Cruz or Rubio with a 0.3 percent lead in the popular vote.
Norpoth’s model showed Sanders losing against Rubio or Cruz with a 0.6 percent gap in the popular vote, giving a Rubio or Cruz ticket a 60 percent chance of winning against the Vermont senator.
Norpoth added that while the non-Trump Republican ticket would be much more unlikely to win the general election due to differences in the popular vote and the electoral college vote, there is almost no chance that Trump would lose the electoral college vote with his forecasted lead in the popular vote.
“If you win by 54 percent [of the popular vote], you have a big majority in the electoral college,” Norpoth said. “Nobody who has ever gotten 54 percent has lost.”