As of Monday, November 4, 83 million Americans had already cast their votes in the 2024 election. On Election Day, Tuesday, November 5, millions more will join them.

Your votes this year will matter more than ever: With 538 forecast for the White House, Senate and U.S. House of Representatives, control of the federal government is firmly in play. Our final models (released at 6 a.m. ET on Nov. 5) give Republicans about a 9 in 10 chance of winning control of the Senate, while the House and presidency are up for grabs. In fact, the race for the White House may be the closest presidential election in more than a century.

the presidency

Let’s start with the race everyone is watching. According Final Presidential Forecast of 538Vice President Kamala Harris has a 50 in 100 chance of winning the Electoral College after all the votes are counted (which could take a few days). We give former President Donald Trump a 49 in 100 chance of winning.* In practice, those odds are virtually indistinguishable—about the same as flipping a coin and getting heads or tails.

Statistically, there is also no significant difference between a chance of 50 in 100 and a chance of 49 in 100. Small changes in the available polling data or in our model settings could easily change a lead from 50 in 100 to 51 in 100 or 49 out of 100. All of this is to say that our overall characterization of the race is more important than precise probability, or which candidate is technically “ahead.”

More than any other factor, our forecast is so close because the polls are so close. According to our final polling averages, the margin between Trump and Harris is 2.1 percentage points or less in the seven swing states. Trump currently leads by 2.1 points in Arizona, 0.9 points in North Carolina, 0.8 points in Georgia, and 0.3 points in Nevada. Harris is up 1.0 point in Wisconsin and Michigan. And in Pennsylvania (the state most likely to decide the outcome of the election), Harris has a slim lead of 0.2 points.

But it’s worth stressing that the polls won’t be exactly right. Polls overestimated Democrats by an average of 3 to 4 points in the 2016 and 2020 presidential elections, for example, and overestimated Republicans by an average of 2.5 points in the 2012 presidential election. Our electoral model expects This year’s polls are expected to be off by 3.8 points on average, although it could be more or less, and our model believes this error is likely to favor both Democrats and Republicans.

In other words, polls in presidential elections should not be expected to be perfectly accurate. They should be expected to be as imperfect as they have been historically. And in a race with very narrow leads for the leader in each key state, that means there is a wide range of potential outcomes in the election.

And that’s why we’ve been saying that the race won’t necessarily be close just because the polls are. Trump and Harris, according to our model, are one normal polling error away from an Electoral College blowup. If we tilt the polls 4 points toward Harris, she would win the election with 319 Electoral College votes:

Meanwhile, Trump would win with 312 electoral votes if polls underestimate him by the same amount:

Hopefully, they can see how uncertain a 50 in 100 chance of winning the election really is. When we say the race for the White House is a toss-up and could go either way, we mean it.

The House of Representatives

In the 2022 midterm elections, Republicans managed to regain the majority in the US House of Representatives. But their performance fell dramatically short of historical expectations, especially in seats where their candidates denied the results of the 2020 election. They ended up winning only 222 seats, barely enough to wield a functional majority (and sometimes it wasn’t even that functional).

Based on the final House forecast of 538, the GOP is in real danger of losing the chamber entirely in 2024. We give them a 49 in 100 chance of controlling the House, while Democrats have a 51 in 100 chance of controlling the House. 100 to take control. . But whichever party wins the majority may find it so narrow as to be ungovernable: the average outcome in our forecast is for the Democrats to win only a one-seat majority.

However, here too there is considerable uncertainty. Because House polls are subject to a lot of error and the other indicators our House uses can be very noisy, our model believes there is about a 1 in 2 chance of a party winning a double-digit majority.

To gain a double-digit majority, Democrats would have to win all of the seats our model rates as “Likely Democratic,” “Lean Democrat,” and “Toss-up” and secure two of the 23 seats we currently rate as “Lean Democratic.” “. ” or “Probably Republican.” Instead, Republicans would have to win all of their “likely” and “few” seats, all of the “contested” ones, and four seats where Democrats are currently favored. Such performances sound ambitious, but it is common that games sweep most or all pitches when they exceed expectations.

One last point on where to expect surprises. We already know that we are not going to elect the “right” winners in every seat. That’s by design. Our goal is not to pick winners; is to correctly estimate the probabilities. And for us to be successful in that regard, candidates with a 75 out of 100 chance of winning must win 75 out of 100 times and lose 25 out of 100. Our final forecast rates 66 seats as “Toss-up.” “Lean” or “Likely.” Based on how well our model would have predicted similar races in past elections, we expect 14 of those districts to go to the party that is not the favorite to win. What’s more, we expect three upsets in districts rated “strong” for either party, meaning they have at least a 98 in 100 chance of winning.

the senate

And now, the race that is decidedly not close: the race to control the Senate. Our model gives Republicans a 92 in 100 chance of winning control of the upper chamber, including scenarios in which they win 51 seats or more and scenarios in which they win 50 seats plus the White House (the vice president breaks ties). in the Senate).**

The Republicans’ strength in our forecast comes from their expected victories in reliably Republican Montana and Ohio, where moderate Democratic incumbents are trying to fend off fierce competition from Republicans. In Montana, the GOP has a 93 in 100 chance of defeating Sen. Jon Tester. In Ohio, Sen. Sherrod Brown has a 41 in 100 chance of beating Republican businessman Bernie Moreno. And our forecast gives West Virginia Democratic candidate Glenn Elliott just a 1 in 1,000 chance of retaining outgoing Sen. Joe Manchin’s seat.

If Democrats lose at least two of these seats, which our forecast should happen about 95 percent of the time, they will need to pick up another seat elsewhere to maintain their majority. According to our forecast, their best chances of making it are in either Florida or Texas, but they only have a 16 in 100 chance of winning each. That’s nothing; it’s about the possibility of rolling a standard six-sided die and getting a 1. But it’s still a pretty uphill climb for Democrats.

Our last word

This is a good time to remind people that our forecasts are not crystal balls. And especially in a year with such close races, they can’t offer more certainty than the data we have at our disposal. The goal of creating election forecasting models, as I wrote last week, is not to provide a hyper-precise, laser-like predictive picture of the election that removes all doubt about what might happen. Rather, it is to give people a good understanding of how the polls could be wrong and what would happen if they were.

In presidential and House elections, if polls deviate from the historically normal, either party could emerge victorious. In the Senate, the polls would have to be more skewed than in 2020 in at least one state. That’s possible, but given the other information available about the seats up for grabs, we think it’s unlikely that Democrats will hold the chamber.

Footnotes

*Technically, Harris has a 50.33 percent chance of winning and Trump has a 49.45 percent chance of winning, and there is a 0.22 percent chance of a tie in the Electoral College. This is why rounded numbers don’t seem to add up to 100 percent.

**In addition to scenarios where Republicans win 50 seats and Nebraska independent candidate Dan Osborn wins his seat and decides not to be part of any party.