Some insights from “Time for Change Model Predicts Close Election with Slight Edge for Kamala Harris” by Alan I. Abramowitz, author of The Great Alignment: Race, Party Transformation, and the Rise of Donald Trump, at Sabato’s Crystal Ball:
The assumption underlying the Time for Change model, which has an excellent track record in predicting the outcomes of presidential elections since 1992, is that the results of these contests are largely determined by three factors: the popularity of the incumbent president, the state of the economy, and the number of terms that the president’s party has controlled the White House.
Not surprisingly, the more popular the incumbent president and the stronger the economy, the better the candidate of the president’s party tends to do. Less obviously, the incumbent president’s party does better when it has held the White House for a single term than when it has been in power for two terms or longer. That is the “Time for Change” factor, and it has a surprisingly strong relationship with the results of presidential elections. Since World War II, the candidate of the president’s party has won 7 of 9 elections after a single term in office but only 2 of 10 elections after two or more terms in office. The public appears to be more reluctant to vote for a change in direction in Washington after only four years than after eight or more years and in 2024, Democrats will be defending the White House after only four years in office. So even though Harris is not a first-term incumbent running for reelection, she does benefit from something of an incumbency bonus in the model because she is seeking just a second straight term for her party in the White House.
Abramowitz notes, further:
Plugging in President Biden’s net approval rating of -18% in late June and the estimated second quarter growth rate of 2.8% in real GDP along with the fact that Kamala Harris will be defending the White House after a single Democratic term in office, the Time for Change model predicts narrow Democratic victories in both the popular vote and the Electoral College. The predictions are a Democratic margin of 2.6 percentage points in the national popular vote and 281 electoral votes, only 11 more than the minimum of 270 needed to win an Electoral College majority.
Based on these results, clearly the safest prediction that we can make about the 2024 presidential election is that it is likely to be very close. Both the predicted popular vote margin of 2.6 percentage points and the predicted electoral vote margin of 24 votes are much smaller than the standard errors of the two regression equations. Adding to the uncertainty of the predictions are the highly unusual circumstances of the 2024 election, especially the replacement of the incumbent president at the top of the Democratic ticket by the incumbent vice president. These results are based on the assumption that Kamala Harris will enjoy the normal advantage that goes to the candidate seeking just a second-straight party term in the White House (typically this person is an incumbent who was elected to the party’s first term in the previous election, but Harris is not).
It certainly would not be shocking if Donald Trump were to win either the popular vote or the electoral vote in the 2024 presidential election. It would also not be shocking if the outcome turns out to be an Electoral College misfire, a split between the popular vote winner and the electoral vote winner. That has happened twice since 2000 and it almost happened again in 2020. Nevertheless, both the popular vote and the electoral vote models give a small advantage in the 2024 presidential election to the Democratic ticket of Kamala Harris and Tim Walz over the Republican ticket of Donald Trump and JD Vance.
Harris has thus far waged a remarkably effective campaign, leading up to Labor Day. If she can hold the current trend line for ten more weeks, Abramowitz’s ‘Time for Change’ model will look even stronger.
