A big debate this election season is whether Democratic support is beginning to wane among Black voters. In February, for instance, Gallup found that only 66% of Black Americans now identify as Democratic, a 16-point drop over the past decade. Some analysts suggest that racial identity has become less predictive of voting patterns in recent elections.
To be sure, Kamala Harris’s emergence as the Democratic nominee changes that conversation to some extent. But if Black voters are supporting Republican candidates in significant numbers, it could pose a challenge for Democrats in close elections. To what extent are Democrats at risk of losing meaningful support from a constituency that has been a core part of the Democratic coalition for over a half-century?
Our analysis of data from recent elections suggests that the story is more complicated – and perhaps less worrisome for Democrats. One reason is that the decline in Democratic support among Black voters has occurred mainly among nonvoters. In addition, we find that while preelection polls indicate rising numbers of undecided Black voters, the vast majority of these voters ultimately vote for the Democratic candidate. Consequently, the polls may make it appear that the decline in Democratic support among this crucial constituency is larger than it actually is at the ballot box – where it matters the most.
Black support on Election Day remains extremely high
Our analysis relies on the Cooperative Election Study, which has surveyed more than 30,000 Americans every election year since 2006. Thanks to the CES large sample size, we are able to measure the attitudes and behavior of Black Americans and other voting blocs, with more precision than most other surveys.
The CES aligns with other surveys in documenting a noticeable decline in Democratic partisanship among Black Americans over recent election cycles. In 2008, 81% of Black adults affiliated with the Democratic Party or Democratic-leaning independents. By 2020, Democratic affiliation among Black adults had dropped to 69%.
Most of this decline, however, is happening among nonvoters. We know this because the CES matches respondents to voter files to distinguish between voters and nonvoters. It’s true that Black voters have seen a modest decline in Democratic partisanship. But the drop has been much more pronounced among Black people who do not vote. In 2012, 80% of Black nonvoters identified as Democrats. This figure fell to 57% in 2020. By comparison, Democratic partisanship among Black voters declined from 88% to 82% during that same time period.
Despite this decline in partisan identification, the two-party vote share for Democratic presidential candidates has remained robust. To broaden the time frame provided by the CES data, we included an analysis of exit poll data extending back to 1980. During this four-decade period, Black support for Democratic presidential candidates stayed consistently around 90%. For example, during the 1980s and 1990s, the share of the Black vote going to Democrats averaged about 89%. That vote share dipped to 87% in 2004, but in the 2008 and 2012 elections more than 95% of Black voters supported Barack Obama. In the past two presidential elections (2016 and 2020), the Democratic ticket won at least 92% of the Black vote. In that context, Black support for the Democratic presidential candidate in recent elections has been modestly stronger than it was in the 1990s and early 2000s.
Preelection vote intentions tell a very different story
In each year’s CES preelection wave, we ask respondents how they intend to vote in the upcoming presidential election. While Black nonvoters expressed similar vote intentions as Black voters in 2012, the two groups have diverged sharply in the past two elections. In 2020, about 90% of Black people who eventually turned out to vote said they planned to vote for Joe Biden. In that same year, only 80% of Black people who did not ultimately vote said the same.
At the same time, Black voters continue to demonstrate consistent support for Democratic candidates – according to CES surveys after the election that ask who they actually voted for. Among nonvoters who were asked which candidate they would have voted for if they had turned out, support for Democratic presidential candidates remained strong in the post-election survey.
This disparity between preelection intent and actual voting behavior illuminates the challenge that polls have struggled with in recent elections: Black nonvoters may be answering surveys in ways that suggest they’re open to abandoning the Democratic nominee. The fact that these individuals ultimately do not vote – or ultimately do support the Democratic candidate – can produce misleading preelection vote share estimates.
One clue that this might be happening comes from 2024 preelection polling on the intentions of likely voters. These polls appear to show a bigger lead for the Democratic ticket, when compared to polls of registered voters. For example, in an April New York Times/Siena Poll Biden received 69% of the vote among Black registered voters but 76% among Black likely voters. Donald Trump’s vote share remained unchanged (at 16%). Thus, the preelection preferences of Black nonvoters could be exacerbating any dip in Democratic support being picked up in the polls.
Most undecided Black voters still back Democrats on Election Day
One reason that preelection polls suggest less support for Democratic candidates than in the past is the fact that more Black voters now say that they are undecided about their vote choice when answering these surveys. Traditionally, Black voters were less likely than white voters to be undecided. But that pattern flipped in 2020, when the percentage of Black voters identifying as undecided rose to 13%. This weakening of steadfast support in preelection polls has been one source of consternation for Democrats.
But our analysis shows the vast majority of Black undecided voters still vote for Democratic candidates, though not quite as overwhelmingly as they did during the Obama elections.
For instance, in 2020, if a poll showed 8% of Black voters were undecided, our research finds that only about 2% of that 8% ultimately voted for Trump (with 6% for Biden). That means Biden’s margin over Trump among Black voters was actually 4 points larger than what the preelection poll would have indicated.
In 2008, by comparison, nearly all undecided Black voters ultimately voted for Obama, but there were fewer of them (only about 4%). So, similarly, preelection polls in 2008 would also have shown Obama’s margin among Black voters to be about 4 points less than it was once the votes were counted.
Black voters remain the most loyal Democratic constituency
To be sure, Black people are less likely to identify as Democrats than they were in the past. And this group is less likely to support Democratic candidates in preelection polls, compared to previous years.
Still, these trends seem largely confined to Black Americans who do not ultimately vote. Undecided Black voters overwhelmingly break for Democratic candidates, a pattern that has led to recent Democratic presidential candidates faring just as well among Black voters as has been the trend over the past several decades.
For 2024, it’s also possible that Harris replacing Biden on the Democratic ticket will energize and mobilize Black voters. Even before Biden dropped out, Harris was already polling 11 points higher than Biden among Black voters. One question is whether Harris will be able to achieve Obama’s historic level of support among this constituency.
Brian Schaffner is the Newhouse Professor of Civic Studies in the Department of Political Science and Tisch College at Tufts University. He also serves as a co-director for the Cooperative Election Study.
Caroline Soler is a senior at Tufts University majoring in political science and mathematics and is a research associate for the Cooperative Election Study.
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