Iowans vote in two weeks. Will the GOP primary end there?

Given his lead now, Trump losing the nomination would be one of the most surprising political outcomes ever

If the polls are perfect (they won’t be!) and they don’t move at all over the next 14 days (they could!) then Donald Trump should end up winning the Iowa Republican Caucus about 30 percentage points; Currently, my polling average for 538 has him at 50% of the vote, versus 18% for Ron DeSantis and 16% for Nikki Haley:

Two weeks ago, when we were merely 4 weeks out from Iowa, I wrote the following for ABC News/538:

According to 538's average of national polls, as of Dec. 15, former President Donald Trump leads the primary race with 61 percent. Florida Gov. Ron DeSantis and former U.N. Ambassador Nikki Haley are essentially tied for second at 12 percent and 11 percent, respectively. Trump also leads by at least 25 percentage points in Iowa, New Hampshire and South Carolina. And when you consider Trump's wide lead alongside how little time remains until voting actually begins, he now looks almost inevitable. Unless a historically unforeseen event happens, Trump is overwhelmingly likely to be his party's nominee next year.

I explained how I arrived at that optimistic case for Trump. As I see it, the probability of winning a single electoral contest (eg, Iowa, rather than the nomination) is a function of the forecast horizon¹ and the historical volatility of the polls for a contest, plus some error term.² In the case of Iowa, historical volatility is rather low in the month before caucus day, and there’s not much time left to go. I explain in the piece:

In the month leading up to both parties' Iowa caucuses since 2008, the average candidate's support in Iowa polls has only changed by about 4 points.

Only in one case did a candidate gain double digits (Santorum in the 2012 GOP primary) — and that shake-up was driven by one candidate (former House Speaker Newt Gingrich) losing significant ground and another (businessman Herman Cain) dropping out of the race entirely. Absent a high-profile dropout ahead of Iowa this year, it's hard to see where any current candidate could gain such momentum.

And, for bonus points, I issued some caveats about using history to predict the future (AKA, remarks about the error term):

There is still a chance that the polls are wrong or that history does not serve as a guide to the 2024 primary. Unknown variables range from whether Trump will be convicted of a felony before officially being nominated in July, to how long his leading opponents will stay in the race and whether Republican voters start to worry that Trump might be "unelectable" in a general election.

But the impacts of these events feel tiny compared to Trump's current commanding lead. Four months ago, he looked like an obvious leader, but not a foregone conclusion. Now, the hopes for his competition lie on a once-in-a-generation political comeback. Do any of them have what it takes?

Now that we are only two weeks out, our models are even more confident of a Trump win in Iowa, which we focus on because it historically has been a catalyst for movement in the national polls. But no presidential candidate polling at over 40 percent in national polls at this point in the primary has ever lost their party’s nomination. Empirically, an eventual Trump win at this point would be a 1 in 100 event, making it one of the most — if not the most — surprising political events in recent history.

So, it’s now officially 2024. The Republican presidential primary will officially begin in Iowa in two weeks. But unofficially, it may also end there.

Thinking beyond the primary

Here are some thoughts about news agendas. I use “beyond” here in terms of both time and scope.

In regards to time, an extended GOP primary would be good for news outlets. Having more eyeballs on news articles and interactives generates more revenue and lasting audience engagement for the primary. But, selfishly, I hope the primary comes to a swift close. That would give us more time to think about nerdy newsroom goals, such as how to interactively explore the likely geographic and demographic patterns in the contest and how to best visualize outputs from election forecasting models. That’s not to say that we won’t do those things if the primary drags on; Indeed, we will have to do both either way, but in the case of a swift end to the primary I get to sleep a little more.

In terms of scope, there is a lot of non-primary political news that media outlets need to focus their attention on. One example is the apparent challenge Joe Biden faces in holding his 2020 coalition together. Another is the ongoing litigation over whether Trump can even appear on the ballot given his participation in the events of Jan 6, 2021. There’s also his increasingly authoritarian rhetoric at rallies, including the much-covered promise to be a “dictator on day one” if elected again. At 538 we talked a bit about this here, but we could probably find new angles for both of these stories if given enough time and data.

My broader point here is that primaries suck up a lot of oxygen at news outlets, both internally and in the products our readers consume. To many observers, Trump emerging from Iowa and Super Tuesday as the de-facto winner of the GOP primary would be a negative signal for democracy. But it would give us some time to cover that story in new ways, which would be good.

Elliott

1. The amount of time between the event in question and whenever we’re making a prediction. In this case, the days remaining before the election (14)

2. The correct error term to use for forecasting election is a matter of some debate