Leader or Party? How Much Each Candidate Drives Their Own Party's Vote

Among Spaniards who voted for the Socialists in 2023, the score they give Pedro Sánchez almost decides whether they will do it again. For the People's Party, Alberto Núñez Feijóo's score matters much less; Santiago Abascal holds on to Vox voters, and Yolanda Díaz's score barely moves Sumar's. That is what 32,000 interviews by Spain's public polling institute show.

21 October 2026 · Miguel · Leer en español

Every campaign brings back the same question: do people vote for a person or for a party? In Spain, the monthly surveys of the Center for Sociological Research (CIS), the government-funded polling institute, let us look at it closely, because they ask three things at once: what score, from 1 to 10, respondents give each national leader; whom they voted for in the last general election; and whom they plan to vote for now.

We pooled the eight CIS surveys from 2026 that include the leader question, fielded from January to September: 32,170 interviews. For each party, we took the people who voted for it in July 2023 and looked at how many say they would vote for it again, depending on the score they give its leader: Pedro Sánchez for the Socialist Party (PSOE), Alberto Núñez Feijóo for the People’s Party (PP), Santiago Abascal for Vox and Yolanda Díaz for Sumar. We compared the results with the CIS pre-election survey of July 2023, which asked the same questions.

One slope per party

If votes depended only on the party label, the score given to the leader would not matter and the lines in the chart would be flat. If they depended only on the leader, they would run from zero to 100.

• PSOE. The steepest line. Among 2023 Socialist voters who give Sánchez a 1 to 3, only 7% would vote for the party again; among those who give him a 9 or 10, 93% would.
• PP. Even voters who give Feijóo a 1, 2 or 3 stick with the PP 29% of the time, and those who give him a 4 to 6 do so 65% of the time. The score matters, but much less.
• Vox. Its line looks like the PP’s at the bottom and like the PSOE’s at the top: 95% of those who give Abascal a 9 or 10 would vote Vox again.
• Sumar. Almost flat: between 41% and 57% would stay, whatever score they give Díaz. Here, “staying” includes voting for Sumar or for Podemos, which ran together in 2023.

One way to sum it up is the loyalty gap between voters who rate their leader 7 or higher and those who do not: 54 points for the PSOE (86% vs. 32%), 35 for Vox, 28 for the PP and 11 for Sumar. With 95% intervals, the ranking is clear except between Vox and the PP, which partly overlap (35 ± 5 vs. 28 ± 3).

Out of every 100 voters

The slope shows how much the score matters; the next chart adds how many people are on each side.

Of every 100 Socialist voters from 2023, 66 would vote for the party again, and 54 of them give Sánchez a 7 or higher: more than eight in 10 of the votes the PSOE keeps come from people who rate its leader highly. The PP’s math is different: it keeps 69 out of 100, but only 39 of them rate Feijóo 7 or higher. Almost half of the vote the PP retains (30 of 69) comes from voters who give him less than a 7.

Where the defectors go also differs. Of the Socialist voters who rate Sánchez below 7 and would not vote for the party again, 36% are still undecided and the rest scatter (PP 17%, blank or spoiled ballot 11%, Vox 11%). Among PP voters who would not stay, the split is nearly even between undecided (37%) and Vox (36%). For Vox, the first destination is Se Acabó La Fiesta (31%), the party Alvise Pérez founded in 2024, ahead of the PP (24%).

What has changed since 2023

• PSOE: nothing. The 54-point gap is exactly the same as in July 2023, and the share of its voters who rate Sánchez 7 or higher has barely moved (65% and 63%). The bond with its leader was already this strong.
• PP: fewer voters who rate Feijóo highly, same effect. In 2023, two in three of its voters gave him a 7 or more; today, fewer than half do (46%). The loyalty gap is still around 30 points: more PP voters are lukewarm about him, but they stick with the party at a similar rate.
• Vox: stable. A few fewer high scores (72% and 63%) and the same loyalty gap (37 and 35).
• Sumar: the big change. In 2023, when Díaz was the candidate, her score mattered as much as Abascal’s (39 points). Today the gap is 11. If we count as loyal only those who would stay with Sumar, without Podemos, the gap rises to 22 points: Díaz’s score shows up more in the choice between Sumar and Podemos than in whether voters stay in that political space at all. Frente Amplio, the new brand of this space, was launched on October 17, after these surveys were taken, and its candidates will be known once the lists are officially proclaimed in early November.

When the leader belongs to another party

The score does not just help keep a party’s own voters. It also goes along with voters who switch parties.

• Of 2023 Sumar voters who give Sánchez a 7 or higher (one in two), 26% plan to vote for the PSOE; of those who give him less, 8%. In 2023 the figures were almost the same (23% and 7%).
• Of 2023 PP voters who give Abascal a 7 or higher (almost one in five), 39% would switch to Vox, up from 27% in 2023.
• In the other direction, Feijóo now draws fewer Vox voters than in 2023: 19% of those who give him a 7 or more would switch to the PP, compared with 43% back then. And fewer Vox voters give him that score: 16%, down from 33% in 2023.
• Díaz draws hardly any Socialist voters: 4% of those who rate her highly, compared with 13% in 2023.

Do other polls see the same?

The CIS has a known bias: in recent elections it has overestimated the PSOE and the left. That is why it is worth checking against other pollsters, although they do not publish their raw data and we can only compare what they release.

On the average score, the CIS is the only one that puts Sánchez clearly first (4.2 in September, on its 1-to-10 scale). Sigma Dos for El Mundo (October 1–8) gives Feijóo a 3.9 and Sánchez, Abascal and Díaz a 3.2 each; NC Report for La Razón, 4.4 for Feijóo and 3.5 for Sánchez; DYM for the Henneo group, 3.6 for Sánchez and one tenth less for Feijóo. Each firm uses its own scale and sample, so these figures cannot be compared to the decimal.

Where they do agree is on what happens within each party’s electorate. In 40dB’s leadership survey for El País and Cadena SER (December 2025), Abascal is the leader with the strongest internal support, with an average score of 8.4 among Vox voters, Feijóo gets more modest ratings among his own voters, and Sánchez is the preferred choice to govern for almost 20% of Sumar and Podemos voters. In Sigma Dos’s October survey, 31% of Sumar voters want Sánchez to remain prime minister.

What these data do not say

This is not cause and effect. The score and the vote intention are asked in the same interview, and they influence each other both ways: someone who has decided not to vote for a party again tends to give its leader a lower score. What this analysis measures is how closely opinions of the leader and votes move together, not how many votes each leader “brings in.”

And it does not predict how the campaign will end. In July 2023 the PSOE’s loyalty gap was already 54 points, and many of its voters who were lukewarm about Sánchez ended up voting for the party anyway. We checked this when building our model: using leader scores to allocate the undecided voters in the 2023 pre-election survey made the estimate slightly worse (from 0.93 to 0.96 points of average error per party). That is why the altnalysis forecast does not use them, and leader ratings are published only as descriptive data on the polls page.

How we calculated it

• Data. Microdata from the 2026 CIS surveys that include the leader-rating question (studies 3540, 3544, 3546, 3557, 3562, 3567, 3571 and 3577; fieldwork from January 5 to September 4; 32,170 interviews) and from pre-election study 3411 (July 2023; 29,201 interviews), weighted with the CIS’s own weights.
• Who counts as a party’s voter. Recalled vote in the previous general election: 2023 for the 2026 surveys and November 2019 for the 2023 pre-election survey. For 2023, Sumar groups voters of Unidas Podemos and Más País in 2019.
• Staying. Saying they will vote for the same party. For Sumar, Podemos also counts, except where noted.
• Uncertainty. 95% intervals based on the effective size of the weighted sample. Differences of a few points between smaller parties are not significant.
• Code. analisis_lideres.py, in the altnalysis repository; the figures in this article come from its October 20, 2026, run.