Don’t ignore South Carolina and Nevada.
by Nate Silver
A common refrain in coverage of the Democratic primary campaign is that the race looks much different in the early states than it does nationally, with a wider playing field, greater strength for upstart candidates such as Pete Buttigieg, and signs of weakness for the leader in national polls, Joe Biden.
The refrain is true if you look only at Iowa or only at New Hampshire, but it’s mostly not true overall. Taken collectively, polls in the four early states — Iowa, New Hampshire, Nevada and South Carolina — tell almost the same story as national polls: Biden leads, Elizabeth Warren is in second, Bernie Sanders is in third, and Buttigieg is still a fairly distant fourth.
There are some differences: Tom Steyer, who has poured millions of dollars into advertisements in the early states, is notably stronger in all four of them than in national polls. But Biden’s position is pretty much the same in the four early states taken together as in national polls. If anything, Warren and Sanders lose slightly more ground in early-state polls relative to national ones than he does.
Overall, among the nine Democrats who have qualified so far for this month’s debate, the correlation between national polls and early state polls (weighted by the number of Democratic voters in each state) is .99, or nearly perfect. It seems like perceptions to the contrary derive from ignoring South Carolina (a strong state for Biden) and Nevada (strong for Biden and also Sanders’s strongest early state) and their more diverse and moderate electorates at the expense of white and liberal voters in Iowa and New Hampshire.
Let’s look at some data. Below, I’ve calculated a polling average in Iowa, New Hampshire, Nevada and South Carolina using polls in FiveThirtyEight’s polling database. Polls are weighted based on their sample size and their pollster rating (please don’t hesitate to check out our newly-updated pollster ratings!). Because recent polling is a bit sparse in some of these states — and because the race doesn’t seem to be changing that much anyway — I’ve gone back and included all polls since the September debate, but polls since the October debate are weighted double. If a polling firm surveyed a state multiple times in this period, only its most recent poll is included. I’ve also calculated a national polling average using the same method. (All polling averages are through early Tuesday.)
The Iowa numbers do look quite a bit different than national polls, with Buttigieg much stronger and Biden much weaker. Interestingly, Warren isn’t doing appreciably better in Iowa than in national polls, perhaps because she loses support to Buttigieg (both are competing for white, college-educated voters). Sanders is a tiny bit weaker in Iowa than he is nationally. Steyer and Amy Klobuchar are slightly stronger.
In New Hampshire, some of the same patterns hold, although less profoundly. And Warren slightly overperforms her national numbers.
But Iowa and New Hampshire’s Democratic electorates are both quite white and quite liberal, which plays to the strength of some candidates more than others. It’s disadvantageous for Biden, who relies on a coalition of black Democrats and moderate, usually non-college-educated white Democrats.
Nevada, which is more working-class and more racially diverse, is a stronger state for Biden, as well as for Sanders, who like Biden does better among voters who did not attend college. And South Carolina, which has both a lot of African-American voters and a lot of moderate white voters, is a very strong state for Biden, as his polling average there (35.7 percent) more than doubles that of the second-place candidate, Warren.
Overall, if you weight the early-state polling averages by the number of Democrats in each state,1 they show Biden at 27.5 percent — similar to his national polling average during this period, which is 28.6 percent. Warren, at 19.5 percent in the early-state average, and Sanders, at 14.2 percent, are actually a bit weaker in early states overall than in national polls. And Buttigieg is at best slightly stronger in the early states; his good numbers in Iowa and to a lesser extent New Hampshire are counteracted by weak ones in Nevada and South Carolina.
The one candidate who really does appear stronger in the early states is Steyer, who averages at least 2.5 percent in each of them — but only registers at 0.9 percent in national polls.
Of course, Iowa and New Hampshire vote first — and could therefore affect voting in the subsequent states, including Nevada and South Carolina. But the media ought to be careful about implying that Biden is especially weak in the early states or that Buttigieg is especially strong in them. Those characterizations only hold if you look at Iowa and New Hampshire, which have electorates that are highly unrepresentative of the Democratic Party as a whole. Biden does just fine in the more diverse early states, conversely.
Put differently, there isn’t much evidence that Biden does worse with voters who see him up close and personal, as often seems to be the implication of coverage that focuses heavily on Iowa and New Hampshire. Instead, he does worse with liberal, college-educated whites, who are plentiful in these states. Intentionally or not, the intense media focus on Iowa and New Hampshire serves to give more influence to liberal, college-educated whites at the expense of African-Americans, Hispanics, moderate Democrats and working-class Democrats, groups that are also key parts of the Democratic coalition.
Nate Silver is the founder and editor in chief of FiveThirtyEight. @natesilver538