Democratic presidential candidate Bernie Sanders speaks during an appearance at Club Passim on April 23 in Cambridge, Mass. (Nancy Lane/The Boston Herald/AP)

There is still another entire NFL season between us and the first voting in the 2020 presidential primaries. If you started counting right now, one number every second, you’d be past 24.5 million by the time Iowans started showing up at their caucuses in February. There is a lot of time between now and then, is the point, rendering detailed analysis of political polling somewhat tenuous.

But not entirely useless. We can get a pretty robust sense of where the Democratic field stands and, importantly, where Democratic voters stand by considering what they’re thinking now and how their voting preferences are changing.

On Tuesday, Monmouth University released the latest of its national Democratic primary polls. The top line won’t be surprising to those who’ve been tracking the numbers: Former vice president Joe Biden leads, with Sen. Bernie Sanders (I-Vt.) in second. Between the two of them, they have the support of more than half of the Democrats (and Democratic-leaning independents) who were interviewed. That hadn’t changed from the previous poll, conducted in March.

Here is the current position of each of the nine candidates who received at least 2 percent support in either of the two most recent Monmouth polls.


(Philip Bump/The Washington Post)

Again, that may look familiar. If we look at how those numbers have changed since March, though, things get more interesting. Here, for example, is how each candidate’s position has changed in the past month.


(Philip Bump/The Washington Post)

(Two housekeeping notes: These graphs will use “Democrats” to refer to both Democrats and independents who lean Democratic. Each chart also shows the candidates stacked so that higher-polling candidates are layered on top of lower-polling ones.)

The candidate who stands out there, obviously, is South Bend, Ind., Mayor Pete Buttigieg. But notice, too, where his eight percentage points may have come from: Sanders is down five percentage points from March.

That transfer is reinforced when we look at the change among self-identified liberals (as opposed to moderate and conservative Democrats). Buttigieg is up double digits; Sanders is down more than other candidates. Lurking behind Sanders there is former congressman Beto O’Rourke (Tex.), who also registered a slide among liberal Democrats.


(Philip Bump/The Washington Post)

(More housekeeping: These swings may not be as large as they look, because of margins of error. In many cases, the changes you see will be statistically insignificant.)

Among white Democrats, the apparent Sanders-to-Buttigieg movement is even more clear.


(Philip Bump/The Washington Post)

Among nonwhite Democrats, though, Sanders actually saw some improvement since March. Buttigieg was basically at zero with most groups in Monmouth’s last poll, so he also saw a slight gain among nonwhite Democrats — but less than what Sanders saw. (We’ll come back to this.)

Biden — not quite a candidate yet — was the one who lost the most support among nonwhite Democrats.


(Philip Bump/The Washington Post)

Let’s look at a different set of numbers: How each candidate fares in the April poll between different groups of Democratic voters. Sanders polls much better with nonwhite voters than white in Monmouth’s new poll, while Buttigieg and Sen. Elizabeth Warren (D-Mass.) do much better with white Democrats.


(Philip Bump/The Washington Post)

Remember, by the way, that Biden still has the lead in Monmouth’s poll. Why? Because of his strong support from more moderate voters. Most of the candidates get more support from liberals than moderates, with Biden being the obvious outlier. (O’Rourke also does slightly better with moderates.)


(Philip Bump/The Washington Post)

Biden has also got the most lopsided support by gender, with men choosing him by seven points more than women do.


(Philip Bump/The Washington Post)

Another place that Buttigieg saw a surge since March was among Democrats with a college degree. That metric corresponds to some extent with age, though the increase in support for Buttigieg was more modest among older Democrats than it was with better-educated Democrats.


(Philip Bump/The Washington Post)

We mention that, though, to point out the wide, ongoing age disparity in support for Sanders. While Warren gets significantly more support from older voters, Sanders gets far more support from younger ones.


(Philip Bump/The Washington Post)

That’s consistent with the support that Sanders enjoyed in the 2016 primaries, as well. While Buttigieg has seemingly eaten into Sanders’s support among white Democrats and liberals, younger voters have remained with Sanders. (O’Rourke, who touts his appeal to younger voters, gets only a fraction of Sanders’s numbers with those under 50 in the new Monmouth poll.)

Those little heads will keep sliding around as the months pass. History teaches us to be skeptical of narrow early-primary leads, so we should be skeptical. But the Monmouth polling does give us at least one important hint of what’s to come: The base of support for the only Democrat in this race who also ran in 2016, Sanders, wasn’t solid enough to prevent a Buttigieg surge over the past month.