Wide open race? Could be...

Earlier this year, we published a three-part series on how well primary polls conducted in the calendar year before a presidential election predict the outcome. Our analysis, which covered more than 40 years of primaries, found that early polls are somewhat predictive of who eventually wins the nomination, especially when they’re adjusted for how well known a candidate was at the time.

So now that we’re halfway through the calendar year before the 2020 election, we decided to replicate that analysis for the current electoral cycle — we used polls conducted between Jan. 1 and June 30, 2019, to calculate a candidate’s (or potential candidate’s) polling average and then adjusted it based on how well known they are (measured on a slightly subjective five-tier scale, which is represented by the black boxes in the table below, where more boxes means higher name recognition).1 This helps us better understand how the 2020 Democratic candidates stack up so far, and how this primary compares to past nomination contests. Here’s where things stand after the first six months of 2019:

How the 2020 Democratic primary field looks six months in

Candidates’ polling averages in the first half of 2019, plus an adjustment for name recognition

In 2020, that likely means that while Biden has rightly been viewed as the Democratic front-runner, he’s not unbeatable. Biden is a long way, for instance, from Hillary Clinton’s position in the last presidential election, when she polled north of 60 percent in the first half of 2015, giving her better than 9 in 10 odds of winning the nomination compared to Biden’s 2 in 5 shot. Candidates such as Warren and Harris also fell into the well-known category, which means historically speaking, their chances aren’t as strong as Biden’s, but if he were to falter, they could benefit from the absence of a clear front-runner. Buttigieg’s low polling average doesn’t bode well historically, but of the candidates who aren’t as well known, he has the best chance of winning the nomination.

In other words, it’s still (almost) anyone’s game. And after the first debate, there are signs that Biden’s lead may be slipping, as multiple surveys have found his support dropping into the low 20s nationally. Meanwhile, Harris and Warren’s percentages have shifted into the mid-teens, putting them and Sanders neck-and-neck behind Biden. This tightening in the race could be quite meaningful, as candidates polling at around 20 percent in the second half of the year before the primaries historically had about a 15 percent chance of winning the nomination. So if the polls continue to trend in the wrong direction for Biden, there might be a new front-runner by the end of the year.

Of course, there will be further twists in the 2020 tale, what with more debates, campaign events and more candidates still entering the race. But if the post-debate polls approximate the new normal for the second half of 2019, watch out — the Democratic nomination race might truly be wide open.