89 Different Scenarios For What Things Could Look Like After Iowa

Maybe you’ve seen articles elsewhere detailing the three or four most likely post-Iowa scenarios, full of elegantly-constructed narratives about how the race might unfold.

This article … is not going to be like that. Rather, it’s just going to be a bunch of rather detailed tables generated by our forecast model, outlining what the Democratic nomination race could look like given the order candidates finish in Iowa and the margins of victory. We hope they’re useful for detail-oriented readers over the course of the evening.

First up: Here’s a table showing the post-Iowa odds a candidate has of winning a national delegate majority given who won Iowa and his or her margin of victory. Specifically, we’re defining a “narrow” win as anything less than 4 percentage points over the second-place candidate, a “medium” win as 4 to 12 percentage points, and a “large” win as more than 12 percentage points. We haven’t listed scenarios if they occurred less than 0.5 percent of the time (at least 50 out of 10,000 simulations) in our final model run. Keep in mind that there is some noise in these numbers; we’ll run a full set of simulations late Monday night or Tuesday morning once we have the caucus results.

The most definitive outcome of the night — albeit a somewhat unlikely one — would be a Joe Biden landslide, which would put his majority chances at 84 percent. Even a narrow Biden win would leave his opponents in fairly bad shape, though.

For a Bernie Sanders win, the margin matters a bit more. A medium-to-large Sanders win could boost his chances of winning the delegate majority to above 50 percent. A narrow win might leave him as the front-runner, but would keep things more competitive.

Wins by candidates other than Biden or Sanders — meaning, Elizbeth Warren, Pete Buttigieg or Amy Klobuchar — would scramble the picture, significantly increasing the chance of no one winning a delegate majority, possibly meaning a contested convention. Of course, any of these candidates winning Iowa would also massively improve their own chances overall. But they’re far enough behind in other states that they’d still have some work to do. For instance, a medium-sized Warren win would give her about a 1-in-3 chance of winning the majority, with Biden also at 1-in-3 and Sanders’s chances significantly diminished but not hopeless.

To add a layer of complication, here’s what you get if you specify the margin of victory and also who the second-place candidate is:

You can see that Sanders and Biden generally wouldn’t mind if Buttigieg or Klobuchar finished in second place, as they are the furthest behind in national polls.

Another fun scenario from the table is what happens if the polls are exactly right, resulting in a narrow Sanders victory with Biden in second place. That would make Sanders the front-runner overall, but not by much, with a 44 percent chance versus 37 percent for Biden.

Buttigieg and Warren finishing first and second in some order would produce the most chaotic outcomes, with at least four candidates still having a plausible shot at the nomination and the “no majority” scenario also still very possible.

Finally, here is a chart showing post-Iowa outcomes based on the order of finish of the top three candidates. I’m going to drop the margin of victory criteria for this one since that produces too many scenarios to keep track of.

This isn’t uncovering too much that you couldn’t have gleaned from the other charts, but note that Biden’s chances could fall to as low as 13 percent in some scenarios if he finishes outside the top 3.

Also note that the model thinks Buttigieg and Klobuchar really need a win outright, as they remain far behind the front-runners in national polls. Finishing a solid second in Iowa might leave open some possibility of their winning the nomination after a long slog, perhaps at a contested convention. But it would make winning via the majority route hard. Warren is slightly more viable with second-place finishes, however, especially if Buttigieg is the winner.