Which voters back which candidates?

Andrew Pasquier
Apr 14, 2020 · 12 min read

An analysis of the ideological positioning of each Democratic primary candidate’s voter base

N.B. Analysis completed during the last week of February proceeding Super Tuesday on March 3rd, 2020


While media coverage of the Democratic primary often emphasizes the ideological “battle” between the progressive and moderate wings of the party, the opposing candidates are, in fact, competing for many voters with similar ideological persuasions. Despite the perceived tension between the moderate party establishment and the party’s electoral base — particularly in regard to the elite’s apparent animosity towards Bernie Sanders — our analyses suggest that, while some differences remain, the vast majority of Democratic voters are considerably more progressive and left leaning than moderate candidates such as Biden and Buttigieg. Nevertheless, electability is increasingly part of a discourse of concern among the establishment, as the candidate who manages to appeal to voters across the ideological spectrum will be the one with the highest chance of winning. While key differences between their platforms and political views remain, our heatmap analyses charting the ideological positions of each candidates’ voters and sympathizers, reveal profound overlap between the five competing candidates’ bases’ political positions in the Democratic political landscape. Whether they back Sanders Bloomberg or Klobuchar, a vast majority of Democratic voters are clustered comfortably within the left-progressive quadrant of the two-axis ideological map. In sharp contrast, the ideological positions of nearly all Trump voters fall within the economically right and socially conservative lower quadrant of the Democratic political landscape. In practical terms, this tendency suggests that despite the divisiveness of the current primary campaign, there remains a lot of shared political ground on which to unite the Democratic electorate for the general election against Trump.


In the sections that follow, we consider how each candidate is staking out different campaign strategies in order to patch together a winning coalition of voters, and we compare that strategy to the ideological positioning of his or her voters and sympathizers.

Joe Biden

Considered the front-runner in the primary race up until the end of last year, former Vice President Biden has staked his candidacy on the belief that most Democrats — and Americans — desire a return to the political normalcy and mainstream progressivism of the Obama years. Up until his disappointing performance in the first three Democratic nominating contests in Iowa, New Hampshire and Nevada, he was considered the candidate best posed to win against Donald Trump. While the general leftward lurch of the party has led Biden to announce his support for programs like universal pre-Kindergarten and new taxes targeting the wealthy, in general, his proposals are modest in comparison to candidates like Warren and Sanders. On health care, Biden strongly opposes Medicare-for-All and instead advocates a centrist approach to “protect and build on Obamacare” — exemplifying a key strategy of his campaign to remind voters of his political experience and ties to the Obama administration.

In alignment with his proudly centrist vision for the Democratic Party, Joe Biden’s epicenter of voter support falls closely to the ideological middle, as can be seen in the heatmaps. Although our survey found Biden sympathizers among the more economically left and socially liberal respondents, his voter base is clearly drawn from the more conservative segments of the Democratic electorate. Unfortunately for former Vice President Biden, he is locked in tight competition with Klobuchar, Buttigieg and late-entry candidate Michael Bloomberg for many of the party’s centrist voters. Although Biden’s recent South Carolina win has fueled hopes of increased momentum in the run-up to Super Tuesday, weak performances in the first primary contests have hurt both his prospects of winning and his claims to be the leading moderate candidate in the race.

Bernie Sanders

Bernie Sanders’ positions long put him on the political fringe of the Democratic Party. In fact, the Senator from Vermont is not even historically a Democrat, instead running as an Independent and self-avowed “democratic socialist”. Yet since his narrow loss to Hillary Clinton in the 2016 primary, many of his once-radical policy proposals like a $15-an-hour minimum wage and “Medicare-for-All” are now popular agenda items for progressive politicians and among voters. Although critics point to Sanders’ uncompromising approach towards advancing his leftist policy proposals as a liability, many supporters respect him precisely for his refusal to water-down his politics to appeal to the traditional mainstream of the party.

Unsurprisingly, Sanders draws his support from the most left-wing and socially progressive voters in the electorate. In our heatmaps, his epicenter of voter support is found above and to the left of Senator Warren’s voter base, despite their relatively similar policy positions. As Sanders’ campaign has gained momentum with victories in the early contests, many have questioned whether the Vermont Senator will be able to expand his base of support beyond the progressive left of the party. In good news for Mr. Sanders, our heatmaps show a spread of sympathizers that extends closer towards the center of the ideological spectrum than his current core voters.

Elizabeth Warren

Competing with Bernie Sanders for the progressive left of the Democratic Party, Elizabeth Warren has emphasized her detailed approach to policy (“I have a plan for that!”) and less polarizing demeanor, in order to differentiate herself from her ideologically close peer. Informed by decades studying bankruptcy as a law professor and her lead role founding the Consumer Protection Financial Bureau after the 2008 recession, Warren strongly condemns the “corruption” of large corporations and their political allies. While Warren, like Sanders, is a huge champion of Medicare-for-All, she has shown a willingness to more slowly phase in the government-run health system in an effort to attract more moderate voters. Overall, on policy issues, little differentiates the core leftist platforms of Warren and Sanders. Instead, personality and semantic differences — like Warren calling herself a “capitalist” — are key distinguishing factors between the candidates.

The heatmaps show that Warren finds the epicenter of her voter base in the progressive left corner of the ideological map. Although many Warren voters are more centrist than Sanders’ core support, her base is clearly drawn from the progressive left-wing of the party. The spatial positions of her sympathizers demonstrate both Warren’s potential to draw more moderate voters, and suggest she has the means of taking support away from Sanders among the most socially progressive (though less so leftist) fringe of the electorate — a contrast encapsulating her struggle to define a winning electoral strategy.

Amy Klobuchar

Much like Biden, Amy Klobuchar refers to her political experience in Washington and more moderate policy stances in making the case to Democratic voters that she is the best candidate to defeat Donald Trump in the general election. Playing up her Midwestern roots, the Senator from Minnesota frequently reminds voters about her record of winning in swing districts in the Midwest that will be key to a Democratic victory next fall. Thus, she has put forward a different version of the electability argument, emphasizing her track-record that, unlike Biden, she has a history of winning a purple state. Her policy platform matches her centrist persona: Klobuchar does not support Medicare-for-all, Universal Pre-Kindergarten or the Wealth Tax. While some of her views, like her more protectionist attitudes on trade, have a left-populist appeal, her stances on social issues, like immigration and gun policy are aimed at courting more conservative voters in the Democratic party.

Klobuchar’s voter base, together with Michael Bloomberg’s, is clustered closely to the ideological center according to our heatmap analysis. While her actual voters are among the most conservative and right-leaning of the Democratic field, Klobuchar interestingly finds many sympathizers among more progressive voters in the primary. The notable skew between Klobuchar’s voters and sympathizers indicates her campaign’s potential to broaden her coalition, should she remain in the race long enough to draw support away from other more progressive candidates.

Pete Buttigieg

While much about Pete Buttigieg’s biography — his age, his sexuality, and his outsider status — initially excited the progressive wing of the party, the candidate has come to pursue a decidedly mainstream campaign appealing to centrist voters. While the 38-year-old former Mayor of South Bend, Indiana, has not shied away from challenging traditional political norms — by calling for the abolishment of the electoral college or the addition of justices to the Supreme Court — he rejects the radical policy platforms of Sanders and Warren as divisive and unrealistic. Buttigieg’s military experience informs more traditional, hawkish foreign policy views, such as his opposition to reducing military funding or a unilateral withdrawal from Afghanistan. Exemplifying his attempts to mix progressivism with policies that can appeal to moderates, Buttigieg has announced his conceptual support for radical ideas like Medicare-for-All and the Wealth Tax, even though his platform proposes more incremental solutions.

Buttigieg finds the epicenter of his voter support exactly where he is trying to stake his appeal: between the progressive left and center of the party. Issues like his free-market attitudes on trade and his more conservative foreign policy may explain the surprising number of voters and sympathizers found in the economically right and culturally conservative quadrants of the heatmap, despite Buttigieg’s non-traditional status as a gay, millennial candidate.

Michael Bloomberg

Michael Bloomberg has entered the Democratic Party presidential primaries with one clear message: Donald Trump must lose the 2020 presidential election. Relying n on his vast pool of personal financial resources, name recognition, and deep networks of support among elites, the billionaire mayor is making the case that he is best poised to win against Trump. He furthermore hopes to capitalize on his credentials as a former Republican, showcasing a capability of attracting moderate voters from across the party divide. He has launched an unorthodox presidential campaign characterized with unprecedented spending on political advertisements that has drawn criticism from many within the Democratic field including Bernie Sanders who accused Bloomberg of attempting to “buy the presidency”. Bloomberg is a moderate candidate, offering on a platform of macroeconomic orthodoxy and emphasis on unhindered international free trade as a means of ensuring US prosperity. Nevertheless, facing credible and ever more popular opponents on the left, the former mayor has adopted certain progressive and left-wing stances, such as tuition-free community colleges, debt-free public universities for low-income students, and carbon pricing. However, given his unreserved support for charter schools and generally all-round moderately conservative positions, a true progressive spirit is far from found.

The heatmaps reveal that Bloomberg’s voter base, along with Amy Klobuchar’s, is among the most conservative within the Democratic electorate, concentrated towards the middle of the Democratic political landscape. While most Bloomberg voters are still located within the left progressive quadrant, a considerable proportion — substantially larger than the voters of any other Democratic candidate — are found in the right conservative quadrant. Contrary to any other candidate’s voter base, Bloomberg’s voters are ‘ideologically split’ in two, suggesting that he has successfully appealed to both traditional Democratic voters — those with a moderately progressive outlook leaning towards the left on economic matters — as well as more conservative Democrats and even former Republicans disillusioned with President Trump, such as himself. This dual epicenter of support bolsters Bloomberg’s claim of being able to appeal to both Democrats and moderate Republicans. Bloomberg’s sympathizers are a more homogeneous electoral group, with their epicenter strongly resembling the one of his more progressive voters. Nevertheless, many Bloomberg sympathizers are slightly more tilted towards the right-wing conservative quadrant than his competitors’.

Donald Trump

Given the highly polarized political climate in the United States, it is unsurprising that most of Donald Trump’s policy positions place him in sharp contrast to all Democrats in the field. On issues ranging from health care and immigration to environmental regulation and taxation, Donald Trump aggressively opposes almost all reform proposals — no matter how moderate — put forward by the range of Democratic candidates. When he ran for President, however, Donald Trump upended traditional Republican orthodoxy in two major areas: trade and foreign policy. What little policy overlap Trump does have with Democrats occurs in these two categories — such as the strong opposition to free trade deals like the Trans-Pacific Partnership — that he shares with Sanders, or his aggressive military position vis-à-vis China that he shares with Biden and Buttigieg.

President Trump’s voter base is found naturally in the bottom right quadrant of the two-axis political spectrum — matching his pointedly right-wing and conservative policy views. There is very little overlap between the ideological position of Trump voters and the support base of any of the Democratic candidates. The more horizontal orientation of the band of Trump voters and sympathizers in the heatmaps indicates how his populist tone on trade and at least surface-level support for public benefits, like social security, have broadened his appeal to socially conservative voters with more populist economic views.


To construct the heatmaps, a survey of 3338 American voters, of whom 1431 are planning to vote for Donald Trump, and 1376 distributed among the Democratic candidates, was fielded in the beginning of February 2020. The remaining 531 respondents filled the survey without indicating a vote intention. Respondents were asked to indicate their agreement or disagreement with the same 30 issue-statements used to map the candidates. The exact positions of voters and candidates are determined through a combination of their respective positions on both axes (the economic “left-right” axis and the cultural “conservative-progressive” axis), resulting in the two-dimensional Democratic political landscape.

Voters and sympathizers are distinguished with the use of a vote intention question and an 11-point scale “propensity to vote” question, with answer categories ranging from 0=”very unlikely” to 10=”very likely”, through which respondents indicate how likely it is that they will vote for the respective candidates. Respondents who answered that they will vote for a specific candidate in the vote intention question are classified as “voters”. Sympathizers are respondents that give a score of 8, 9 or 10 to a certain candidate on the “propensity to vote” question but report an actual vote intention for another candidate. To avoid overlap, respondents who gave a candidate a vote propensity of 8 or higher and also indicated they would vote for that same candidate were logically excluded from the pool of sympathizers of this candidate (as they were already counted as core voters).

Since Andrew Yang dropped out of the race while survey data was still being collected, his name had to be excluded from the vote intention question answer categories. Due to a lack of data, no heatmaps for Yang voters and sympathizers were created.

Text by Andrew Pasquier, Tom Etienne, Yordan Kutiyski, Dr. André Krouwel
Data by
Tom Etienne, Yordan Kutiyski, Andrew Pasquier, Richard Furstein
Graphs by Ognjan Denkovski

The research for this article was conducted by Kieskompas — Election Compass and commissioned by FES. The original publication in German can be found here, as well as its report. The U.S. Democratic Primaries’ Election Compass can be found here.

The U.S. Democratic Primaries Election Compass

The Election Compass is a “Voting Advice Application”, a…

Andrew Pasquier

Written by

The U.S. Democratic Primaries Election Compass

The Election Compass is a “Voting Advice Application”, a popularized academic tool comparing citizens’ opinions to their political candidates’ positions on the most prominent and contentious issues in the campaign. Try it yourself at usa.electioncompass.org!

Andrew Pasquier

Written by

The U.S. Democratic Primaries Election Compass

The Election Compass is a “Voting Advice Application”, a popularized academic tool comparing citizens’ opinions to their political candidates’ positions on the most prominent and contentious issues in the campaign. Try it yourself at usa.electioncompass.org!

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