What We’ve Gleaned About The Democratic Primary From 6 Months Of Polls

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:

Perhaps unsurprisingly, the two candidates who are actually running and have near-universal name recognition sit at the top of the pack. Former Vice President Joe Biden led the way — he regularly topped most nationwide surveys, even before he officially entered the race on April 25 — and Sen. Bernie Sanders finished a distant second, which may speak to holdover support from his 2016 bid for the Democratic nomination. But this isn’t necessarily good news for Biden or Sanders; in the past, some candidates who were well known early in the primary process wound up having trouble growing their support, including then-Sen. Hubert Humphrey in the 1972 Democratic primary and former New York Mayor Rudy Giuliani in the 2008 GOP contest, both of whom fell short of the nomination after fairly strong starts. Not every well-known candidate flops, of course — former Vice President Walter Mondale, for example, improved his poll position and went on to win the Democratic nomination in 1984. But the struggles of people like Giuliani and Humphrey serve as an important reminder that when voters are already very familiar with a candidate, it can be harder to earn more support in the polls, since many voters’ attitudes about the candidate may already be fixed.

That’s why the next couple of candidates in the table might prove to be the most interesting to watch as the Democratic primary heats up. Even though these candidates have smaller national profiles than Biden and Sanders, they still did relatively well among the voters who knew about them. Elizabeth Warren and Kamala Harris, for example, are fairly well-known senators who still don’t enjoy the same level of fame as Biden or Sanders. So the fact that they polled close to 10 percent despite not being as well known suggests they might have higher ceilings of potential support, which is reflected in their adjusted polling average. And the most striking example of a lesser-known candidate polling well in the first half of the year was Pete Buttigieg, the mayor from South Bend, Indiana, who was virtually unknown at the start of his campaign but still managed to attract an outsized share of support. Buttigieg wasn’t one of the five candidates who cracked 5 percent in their unadjusted polling average, but he might still be in a better position than former Texas Rep. Beto O’Rourke, who edged him out in the polls. Like Buttigieg, O’Rourke isn’t that well known, but he didn’t outperform his adjusted polling average by nearly as much.

But how do the candidates running in 2020 stack up historically? Well, to get a sense of their chances, we can see where they fall on a chart from our primary polls series where we estimated a candidate’s chance of winning the nomination based on their unadjusted polling average and whether they had high or low name recognition.² And as you can see below, we found that a well-known candidate polling at 30 percent in the first half of the year had about a 40 percent chance of winning the nomination, while a lesser-known candidate polling around 10 percent had about a 25 percent chance of winning.

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.