The PSOE and Women: Where Its Undecided 2023 Voters Are and How Many Seats They Are Worth

In the 2026 CIS barometers, 15.5% of women who voted for the PSOE in 2023 still do not know whom they will vote for, compared with 10.9% of men. That is about 700,000 voters. They rate Pedro Sánchez better than average and most are over 35. If the PSOE won back half of them, it would gain about three seats. If it won back all of them, about seven. That is a lot in the race for first place, but not enough to change the majority.

27 October 2026 · Miguel · Leer en español

The context

Several media outlets have described the first phase of the Socialist pre-campaign as heavily focused on Pedro Sánchez and his personal circle, and some analysts have read it as a message aimed mainly at the female electorate. Here we do not assess the message or its effectiveness, which can only be measured with polls in the coming weeks. What we can measure is the size of the audience it is, in theory, aimed at: how many 2023 Socialist women voters are undecided today, how old they are, what they think of Sánchez and how many seats they would be worth.

The data are the microdata from the last four CIS barometers (studies 3567, 3571, 3577 and 3582, with 17,110 interviews). We use direct voting intention, not the estimate the CIS publishes. Because the CIS overrepresents the PSOE (we analyzed this in “The CIS Under Examination”), what is useful here are the differences between groups, not the levels.

Women, more Socialist and more undecided

Direct voting intention for the PSOE is 27.5% among women and 20.9% among men, a gap of almost seven points. It is the same figure women gave in the 2023 pre-election survey (27.5%); among men it has dropped slightly (from 21.6%). Women are also more undecided: 18.6% say they still do not know whom they will vote for, compared with 11.9% of men.

The most relevant difference is among those who voted for the PSOE in 2023:

• Women: 15.5% of those who voted for the PSOE in 2023 have not decided. Among those aged 18 to 34, 17.8%; aged 35 to 54, 16.4%; aged 55 and older, 14.3%.
• Men: 10.9%. Only among those aged 35 to 54 does it come close to women (14.4%).

At the same point in the 2023 campaign, 12.7% of women who had voted Socialist in the previous election were undecided, and 11.4% of men. Female indecision has grown by three points; male indecision, barely half a point.

Loyalty to the PSOE rises with age in both sexes: 71% of women aged 55 or older would repeat, compared with 52% of those aged 18 to 34. Among young women, the leakage does not go to indecision but to other parties: 30% of Socialist voters of that age in 2023 plan to vote for another party. That is another battle, largely with Frente Amplio and Podemos, which a message centered on the leader need not resolve.

What they think of Sánchez

Women rate Sánchez better than men at every age: 4.5 on average compared with 4.0. The gap is larger among the young (4.6 versus 3.3). Of women, 34% have a lot or quite a lot of confidence in him, compared with 28% of men. And undecided Socialist women are not hostile to him: they give him a 4.8, more than the average for women.

This is the finding that gives sense to a leader-centered strategy: the electorate it targets does not reject Sánchez, but has not yet decided whether to vote for him. It is a receptive audience, at least in principle. By age:

• Over 55: they rate him best (4.9) and trust him most (39%), but they are already the most loyal. They have less left to win back.
• Ages 35 to 54: this is the largest group and the coolest toward Sánchez (4.1, with 29% confidence), but 16% are undecided. This is where a message aimed at women has the most to gain and the most to prove.
• Ages 18 to 34: they rate Sánchez reasonably well (4.6), but their leakage goes mainly to other parties. The message competes here with Frente Amplio and Podemos.

How many seats they are worth

According to the CIS, women are 59.3% of those who voted for the PSOE in 2023. Applying the share of undecided women to the 7.76 million Socialist votes in 2023 gives about 713,000 voters. We added those votes to the forecast’s 50,000 simulations, in different proportions and distributed by province like the 2023 Socialist vote. We then repeated the seat allocation. Part of those votes is already in the forecast, because polls allocate the undecided like everyone else, and we subtracted it.

• If it wins back one in four undecided women, the PSOE gains 1.7 seats on average; with half, 3.4; with all of them, 6.7.
• With undecided men, the effect is roughly half, because there are fewer of them: 1.6 seats if it wins back half.
• Where those seats come from: mainly from the PP (-3.3 in the extreme case) and from Vox (-2.0).

In the most favorable scenario, with all the undecided women back, the probability that the PSOE has more seats than the PP rises from 15% to 27%. The probability that the PP and Vox add up to an absolute majority falls from 95% to 90%. In other words, the undecided female electorate decides a number of seats and could bring the PSOE closer to first place. On its own, it is not enough to change the majority.

What to keep in mind

• The CIS is not the result. The CIS’s direct intention overrepresents the PSOE and its voters. The proportions between groups are more reliable than the levels, and the absolute voter numbers are an approximation.
• “Don’t know” is not “I’ll come back.” Some of the undecided will end up voting for another party or not voting. The scenario of winning them all back is a ceiling, not a forecast.
• We do not measure the message. We do not know how many women it reaches or how they receive it, and a message like this can also mobilize voters of other parties in the opposite direction. What the data show is where the margin is, not whether it will be used.
• Age matters more than sex for loyalty. What most separates Socialist voters who stay from those who leave is age, not sex. A message aimed at women reaches very different electorates depending on the generation.

How we calculated it

• CIS. Microdata from barometers 3567, 3571, 3577 and 3582 (2026), with their weighting, and from the 2023 pre-election survey 3411 as a comparison. Direct voting intention (INTENCIONGR), 2023 vote recall (RECUVOTOGR), rating of Pedro Sánchez from 1 to 10 and confidence in the prime minister.
• Scenarios. Votes the PSOE wins back: 7.76 million votes in 2023 × the weight of the sex in its electorate according to the CIS × the fraction undecided × the fraction it wins back, minus the part the forecast already attributes to it (its vote share). They are distributed by province like the PSOE’s 2023 vote, added to each simulation of the day’s forecast, and D’Hondt is repeated with the 3% threshold.
• Code. analisis_mujeres_psoe.py, in the altnalysis repository.