2024 Presidential Forecast Update: September 10

A GOOD DAY FOR HARRIS

Strong state-level polling drives a few-point surge in her chance of winning

What changed in today’s model run?

First off, thank you for visiting. If you missed it, we launched our Presidential Forecast model yesterday and, if you’re interested in the methodology, we talk a lot about our assumptions and methods in that piece.

The biggest change is visible in the big red and blue text just below. Harris surged upward by a few points in today’s model run, almost notching a 58% chance of victory in today’s 10,000 simulations.

With 10,000 simulations:

HARRIS WINS 5772 (~58%)

TRUMP WINS 4152 (~42%)

NO WINNER 76 (<1%)

This, of course, came at the expense of Trump’s odds. He wins about 4% (or 400) fewer simulations today than yesterday. Looking at the simulated electoral college margin distribution below, we can see a clear edge in Harris’ favor with more victories on her side of the plot as it begins to skew ever so slightly toward her.

Of course, the center of the distribution still holds a vast density of Trump wins. This is still a very, very close race. We’ll talk about the changes that made this race just a bit less close today in the next section below.

Image on the left showcases the electoral vote margins for each candidate with Harris in the right (blue) and Trump on the left (red).

A look at some of the states driving the model’s movement

HARRIS NOW LEADS IN NORTH CAROLINA

The big news in today’s model run comes from North Carolina. Some strong polling from Quinnipiac and SurveyUSA this week saw her now, just barely, pull ahead of Trump in her chances of winning the state. It is still extremely close, but it’s a race that she has the slightest edge in. Her odds of winning the state crept up from 49.03% to 50.21%. That is a fairly dramatic one-day shift. These are driven by a few polls in particular and could quite feasibly be overpowered by future polling. But, for now, this is big news for Harris.

HARRIS GAINS GROUND IN FLORIDA

You’re not going crazy. In fact, Harris had some strong polling in Florida this week. Two polls are driving some movement here: a Morning Consult poll with Harris at 47 to Trump’s 49 and a poll from Emerson last week with Harris at 48 to Trump’s 51. These polls when viewed individually suggest something more of a toss-up – which would be remarkable in a state that has drifted relatively quickly away from Democrats. Of course, other polling still balances this race out with better numbers for Trump, meaning this state is still much more likely to be in Trump’s column.

Today, her odds in Florida are about 26.57% to Trump’s 73.43%. That’s about 3% more than her chances yesterday. Whereas Florida was ranked in our model as just barely “Likely” Republican instead of “Safe” Republican, it’s now looking like it’s trending toward being more competitive and possibly a thorn in the side for both Republicans and Democrats once more.

HARRIS GAINS GROUND IN VIRGINIA

The state moved solidly from “Likely” Democratic to “Safe” Democratic with Harris now above an 80% chance of winning – specifically, the model now has her at 85% after some strong polling in her favor. This reduces some uncertainty for her victory in the model runs.

HARRIS LOSES GROUND IN TEXAS

Interestingly, Harris is polling better in Florida than in Texas. A Morning Consult poll with Trump leading by 9 pushed her odds down in this state considerably. She is now winning about 14% of the time to Trump’s 86%. This puts Texas back into the “Safe” Republican category now that Trump’s odds are above 80% in the state.

HARRIS LOSES GROUND IN GEORGIA

This is only a minor change, but Harris dropped from 44.49% in Georgia to 42.27%. The state was just barely in the “Lean” Republican category, but now it’s more firmly in that position. It is odd to see North Carolina polling being much more favorable to Harris than Georgia, but perhaps that will be different now that people are tuning in to the election more post-Labor Day.

Swing & Interesting State Shifts Since Yesterday:

The New Map

Despite the relatively large change in Harris’ national probability today, the map itself has barely changed. Even with NC tilting in her favor and Florida beginning to tighten, the only change visible on the map is Texas shifting from “Likely” Republican to “Safe” Republican.

Interestingly, if her national polling improves even a little bit, we may even South Carolina shift closer to “Likely” Republican territory. Only time will tell.

For now, this race is still extraordinarily close and could deliver a win to either candidate.

Thanks for reading, and please be sure to share and engage in the conversation below!

One response to “2024 Presidential Forecast Update: September 10”

  1. […] Welcome back to the Partisan-Gravity Presidential Forecast model. If you missed it, you can catch up on the models methodology here and yesterday’s update here. […]