Last week, we introduced a method for evaluating Democratic presidential contenders, which focused on their ability to build a coalition among key constituencies within the party. In particular, our method claims there are five essential groups of Democratic voters, which we describe as:

Party Loyalists, who are mostly older, lifelong Democrats who care about experience and electability. The Left. Millennials and Friends, who are young, cosmopolitan and social-media-savvy. Black voters. And Hispanic voters, who for some purposes can be grouped together with Asian voters.

The goal is for candidates to form a coalition consisting of at least three of the five groups.

I certainly wouldn’t claim that this is the only way to evaluate the field; rather, it’s part of what we hope will be a fairly broad toolkit of approaches that we’ll be applying as we cover the Democratic candidates at FiveThirtyEight over the course of the next 18(!!) months. Furthermore, in reality, the various ideological and demographic constituencies within the Democratic Party are more fluid than this analysis implies. Nonetheless, it has influenced my thinking — the coalition-building model has made me more skeptical about the chances for Bernie Sanders, Joe Biden and Amy Klobuchar, for instance, but more bullish about Kamala Harris, Beto O’Rourke and Cory Booker. In this article, I’ll go through a set of 10 leading contenders and map out their potential winning coalitions; we’ll tackle some of the long-shot candidates later on this week.

Let’s start with the man who has led most polls of the Democratic field so far, former Vice President Joe Biden. One lesson from the 2016 Republican primary might be to approach the polls with more humility. If a candidate is ahead in the polls for a sustained period of time — as Trump was for much of late 2015 and early 2016 — maybe we journalists ought to give a certain amount of credit to that, rather than just chalking it up to high name recognition or becoming overly wedded to some theory about how voters are “supposed” to behave.

With that said, there are some trouble signs for Biden. He performs worse among those voters who are paying the most attention to the primary, suggesting that his high name recognition compared to most other candidates is a significant factor in his lead.

And I’m not sure it’s going to be very easy for Biden to expand his coalition beyond the 25 percent or so that he’s getting in polls now. Presumably many of those voters are Party Loyalists, a group for whom he’s a good fit. Biden also has strong ratings among black voters, perhaps in part as a result of his being Barack Obama’s vice president — although his handling of the Anita Hill hearings and hawkish stance on criminal justice issues could give him problems among black voters if his record is subjected to greater scrutiny.

But where does Biden go after that? Could he gain support from The Left? Maybe a bit, but his dalliances with economic populism are more rhetorical than substantive; Biden’s voting record, and it’s a long one, is fairly centrist on economic policy. Could he win over Hispanic voters? Perhaps, as Hispanics sometimes back establishment-friendly nominees (like John Kerry in 2004), but Biden’s home state, Delaware, doesn’t have very many Hispanic voters (it has quite a few African-Americans, by contrast) and I’m less willing to give credit to a politician who hasn’t historically had to develop a relationship with a minority constituency. Still, a (Hillary) Clintonian constituency of Party Loyalists, black and Hispanic voters is probably Biden’s best bet.

When I originally conceived this article, I’d planned on splitting the Democratic electorate into three rather than five groups, which I’d roughly thought of as “white Hillary Democrats,” “white Bernie Democrats” and “nonwhite Democrats.” You can probably see why I abandoned that framework. One of the problems with it is that it groups blacks, Hispanics and other racial minorities together when (as in 2008) they sometimes gravitate toward different candidates.

But another problem is that what I had thought of as “white Bernie voters” is also really two different groups: Voters who belong to The Left and those who belong with the Millennials and Friends group. In 2016, Sanders got slightly more than 40 percent of the Democratic vote nationally, which corresponds to winning clear majorities of those two groups, plus making some inroads with younger black and Hispanic voters later on in the campaign. This year, he’s polling at a little less than 20 percent. The most obvious interpretation is that, while Sanders has held on to much of his support on The Left, millennials were mostly just looking for an alternative to Clinton, and they are now considering abandoning Sanders for younger, flashier alternatives such as Beto O’Rourke and Kamala Harris.

So how does Sanders form a winning coalition? He probably does need the millennials to return to his camp, which might happen if the field narrows and his major competition is, say, Joe Biden — but it would be trickier against a Beto or a Harris or a Cory Booker. (Hence the Beto-Bernie wars.) And finding a third coalition partner is even trickier. Party Loyalists are liable to be bitter over his treatment of Clinton in 2016 and over the fact that Sanders is not actually a Democrat. Even groups such as unions — important bridges between The Left and the establishment — have been hesitant to support Sanders’s candidacy.

As for black and Hispanic voters, maybe Sanders can hope that his weak performance among those groups in 2016 was more a matter of Clinton’s strengths than his own liabilities. Sanders’s favorability ratings are reasonably good among black and Hispanic voters, in fact. But a recent survey of influential women of color found very little support for Sanders — and in contrast to four years ago, he’s now running in a field that will likely contain a number of black and Hispanic candidates. Overall, Sanders looks like a candidate with a high floor but a low ceiling, and one who would probably benefit from the field remaining divided for as long as possible.

Warren has somewhat similar problems to Sanders, including having to build a relationship with black and Hispanic voters after being elected from an extremely white state — and having already made a misstep on issues of racial identity when she took a DNA test to “prove” she had Native American ancestry.

But she potentially has a higher ceiling because she’s more likely to win support from Party Loyalists, given that she’s a Democrat rather than an independent, and that she doesn’t have baggage from 2016. She’s also ever-so-slightly to Sanders’s right in a way that places her closer to the median Democratic voter.

The most likely winning coalition for Warren, in fact, probably involves the three predominately white groups: The Left, Party Loyalists and Millennials and Friends. (One of the things that helps her with millennials is that Warren has a bigger and better social media presence than you might assume.) Her path is tricky; she probably needs Sanders to founder. And that’s before getting into the gender dynamics surrounding her campaign and whether misogyny might hurt her chances. But she has a head start, having been the first of the big names to take official steps toward running and having hired key staffers in Iowa and elsewhere, which could give her more time to figure out a winning approach.

O’Rourke has one of the more obvious three-pronged coalitions: He’d hope to win on the basis of support from Millenials and Friends, Party Loyalists and Hispanics. The groups might support him for somewhat different reasons, and O’Rourke won’t win any of them without a fight, but he has a clearer path than the other Democrats we’ve mentioned so far.

O’Rourke really did help to motivate a surge in young voter turnout in his Texas Senate race last year; voters aged 18-29 were 16 percent of the electorate in 2018 as compared to 13 percent in the previous midterm in 2014. And overall turnout was up 80 percent as compared with 2014. O’Rourke won young voters overwhelmingly, whereas in 2014, Democratic nominee David Alameel had actually lost that group to Republican incumbent John Cornyn. O’Rourke also has one of the better social media presences among the Democratic contenders.

Meanwhile, the Democratic Party establishment has been encouraging O’Rourke to run, presumably because they see him as electable and potentially able to raise gargantuan sums of money for the party. Electability is a fuzzy concept, and one should be careful not to let “electable” become a synonym for “good-looking white guy” and vice versa. With that said, O’Rourke’s performance in Texas was quite strong relative to the partisanship of the state — even though he lost to Ted Cruz (by just under 3 percentage points), it was the best performance for a Democrat in a high-profile statewide Texas race in years. His policy views are a bit squishy, but that could also be an advantage of a sort — the same could be said of Obama in 2008 and Trump in 2016.

There’s liable to be a Big Discussion at some point about Beto’s authenticity among Hispanic voters. O’Rourke has a Hispanic nickname, Beto, but his given first name is Robert and he doesn’t actually have any Hispanic ancestry. With that said, he represented a district in El Paso that is almost 80 percent Hispanic, and he beat an incumbent Hispanic Democrat to first win the seat in 2012. He also won 64 percent of the Hispanic vote against Cruz (who is Cuban-American ), which is pretty good in a state where the Hispanic vote can be more conservative than in other parts of the country. (Alameel won just 47 percent of the Hispanic vote in 2014, by contrast.)

The candidate who looks best according to the coalition-building model is probably not O’Rourke, however. Instead, it’s California Sen. Kamala Harris, who potentially has strength with all five groups.

Harris, who is of mixed Jamaican (black) and Indian descent, was easily the top choice in the survey of influential women of color that I mentioned earlier. So while I don’t automatically want to assume that nonwhite candidates will necessarily win over voters who share their racial background — it took Obama some time to persuade African-Americans to vote for him in 2008 — Harris seems to be off to a pretty good head start. And her coalition not only includes black voters, but also potentially Asian and Hispanic voters. Harris did narrowly lose Hispanic voters to Sanchez, a Hispanic Democrat, in 2016 (while winning handily among Asian voters). But her approval ratings among Hispanic voters are high in California, a state where the group makes up around a third of the electorate.

If black voters and the Hispanic/Asian group constitute Harris’s first two building blocks, she’d then be able to decide which of the three remaining (predominately white) Democratic groups to target to complete her trifecta. And you could make the case for any of the three. Harris polls better among well-informed voters, which could suggest strength among Party Loyalists. She’s young-ish (54 years old) and has over 1 million Instagram followers, which implies potential strength among millennials. (And remember, Democratic millennials highly value racial diversity.) Harris’s worst group — despite a highly liberal, anti-Trump voting record — might actually be The Left, the whitest and most male group, from which she’s drawn occasional criticism for her decisions as a prosecutor and a district attorney.

Overall, however, this is a strong position for Harris. As Slate’s Jamelle Bouie points out, it may actually be a strategic advantage to be a black candidate in this Democratic primary in 2020.

If Harris rates strongly by this system, then it might follow that New Jersey Sen. Cory Booker, who is also black, would look strong as well. Indeed, Booker may be somewhat overlooked by the pundit class. He’s been pretty explicit about the fact that he’s eventually going to run for the nomination. And he scored strong favorability ratings in a recent survey of Iowa voters, although he isn’t yet many voters’ first choice.

With that said, there are a couple of areas in which Booker could fall a bit short of Harris. New Jersey doesn’t have as many Hispanic or Asian voters as California does (and Booker isn’t part Asian, as Harris is). And if The Left has some problems with Harris, it’s liable to have a lot of problems with Booker, who many leftists see as being too close to Wall Street and to big business. Winning on the basis of a coalition of black voters, Party Loyalists and Millennials and Friends is certainly plausible for Booker, but he doesn’t have quite as many options as Harris does.

As I said earlier, I don’t think this five-corners metric is the only way to judge the candidates. And there are other heuristics by which Klobuchar, the Minnesota senator, might be better positioned. For instance, if Democrats are looking for a candidate who forms the best contrast to Trump, she has a pretty good case, as a woman from the Midwest who comes across as temperamentally moderate and without a lot of Trumpian bombast.

But I’m not quite sure how she builds a winning coalition. Klobuchar is potentially a near-perfect choice for Party Loyalists, who are liable to see her Midwestern moderation as being highly electable, especially after she won her Senate race by 24 percentage points last year in a state where Trump nearly defeated Clinton. Beyond that, though? Minnesota is a pretty white state, so Klobuchar doesn’t have a lot of practice at appealing to black, Hispanic or Asian voters. Her voting record is fairly moderate — she’s voted with Trump about twice as often as Booker has, for example — so she’s not an obvious fit for The Left. Millennials, perhaps? Her social media metrics so far are paltry — she has just 140,000 Twitter followers, for example — although (not totally unlike Warren) she has a goofy relatability that could translate well to Instagram and so on.

Klobuchar’s chances probably depend more on “The Party Decides” view of the primary than the more voter-centric vision I’ve presented here. In that view, party elites and Party Loyalists are leading indicators for how the rest of the party will eventually vote. One can imagine Klobuchar gaining traction if she performs well in Iowa, for instance. That’s a lot of “ifs,” however, whereas other candidates would seem to have more straightforward paths.

Another Midwestern senator, Ohio’s Sherrod Brown, in some ways has a more obvious route toward building a coalition. Like Klobuchar, he can make some good arguments about electability, having been elected three times in an increasingly red state, potentially making him an appealing choice to Party Loyalists. But he’s also a tried-and-true economic populist, who would be able to build alliances with The Left, and he’s reportedly a top choice among labor unions.

Where Brown might pick up the third group for his coalition is harder to say. Ohio has a reasonably large black vote, so he may be able to appeal to African-American voters. His limited social media presence and rumpled demeanor wouldn’t seem to make him a natural fit for millenials, although rumpledness didn’t stop Sanders from gaining traction with millennials four years ago. Domestic violence allegations against Brown, stemming from his divorce in 1986, have historically not moved the needle against him in his Ohio campaigns but could be a concern to younger voters, especially younger women, if they’re litigated on the national stage.

Gillibrand, who looks increasingly likely to run, sometimes gives the impression of having conducted an analysis like the one you’re reading in this article and taking a color-by-number approach to the Democratic primary. But it can come out a bit awkwardly. On the one hand, Gillibrand has the lowest Trump Score of any senator, meaning that she has opposed Trump more often than any other Democrat in the upper chamber. On the other hand, she once took relatively conservative stances on gun control, immigration and other issues when serving in Congress as a representative from upstate New York. On the one hand, she uses leftist and feminist terms such as “intersectional” to describe how she sees the future. On the other hand, she has ties to Wall Street (as many New York Democrats do).

Gillibrand’s most natural path might be to start with Party Loyalists and build out a coalition from there. But her calls for Sen. Al Franken to resign — issued after several women accused him of groping them — reportedly triggered a backlash among some donor-class Democrats, who [warning, editorial comment ahead] apparently don’t care how stupid they look for blaming a woman for a man’s #MeToo problems.

With all that said, Gillibrand potentially has a reasonably high ceiling. In New York state, she has high favorability ratings among nonwhite voters and an especially large gender gap in how voters view her. So if she isn’t getting a lot of buzz among white male Democratic pundits, you should be a little bit wary about concluding that the lack of buzz is representative of the broader Democratic coalition.

We’re getting toward the end of what you might consider the top couple of tiers of Democratic candidates. And I’m not quite sure whether to consider Castro, the former mayor of San Antonio and former Secretary of Housing and Urban Development, as one of the frontrunners or as more of a long-shot candidate. In the recent Selzer/Des Moines Register poll of Iowa, almost two-thirds of likely Democratic caucusgoers didn’t have an opinion about Castro either way. And neither his tenure as mayor nor his job as HUD Secretary necessarily required him to weigh in on the major issues of the day. So for better or worse, he’s starting out with a relatively blank slate and a malleable policy platform.

Castro does have the advantage of being potentially the only Hispanic candidate in the race. He’s a good speaker, having given the keynote address at the 2012 Democratic convention. And he’s been relatively explicit about his desire to run — he may even officially declare his intentions in the next few days. A coalition of Hispanics, Party Loyalists (if he can persuade party elites about the importance of the Hispanic vote) and Millenials and Friends might be Castro’s best option. As it happens, that’s also O’Rourke’s coalition, so the two Texans could represent a problem for one another.

There’s about an 80 percent chance that the Democratic nominee will be one of the 10 candidates I just mentioned, according to betting markets. Still, that does leave some room for a long shot, and there are literally dozens of other Democrats who are contemplating a presidential bid. There are also some candidates, such as Georgia’s Stacey Abrams, who don’t seem especially likely to run, but who could be formidable if they did. We’ll cover some of those other Democrats in “lightning round” fashion in a third and final installment of this series later this week.





Nate Silver reviews the FiveThirtyEight Midterm forecasts