This analysis aims to calibrate qualitatively and quantitatively the victory scenarios of Reyes Maroto and Enma López in the PSOE primaries for the city of Madrid on July 19, 2026, to designate the mayoral candidate, after both having secured the necessary endorsements to compete. Obviously, the decision lies in the hands of the 5,485 members eligible to vote, and no one can predict the result with absolute certainty. However, both past experiences in PSOE primaries and the trend shown by the endorsements submitted allow for an informed predictive exercise.
Quantitative analysis
Starting with the second point, endorsements are an interesting starting point because they mark an initial trend. In general, we can view endorsements as a precursory vote, assuming a high correlation between the endorsement and the vote cast at the ballot box. However, it is true that an endorsement is a “public” vote and, therefore, does not have the same secrecy as the ballot vote, so there will necessarily be a deviation, of a magnitude difficult to estimate, between the endorsement and the vote.
In this case, it is evident that there is a candidate backed by the regional and federal PSOE machinery (Reyes Maroto) and an outsider candidate (Enma López), something confirmed by the anger provoked by her candidacy and her departure from the Federal Executive Committee. Therefore, it is logical to assume that a portion of Maroto’s endorsements will not translate into real votes, but will be endorsements of courtesy or to appease the leaders. In López’s case, the deviation is assumed to be statistically irrelevant, since those who have publicly supported the outsider have no reason not to vote for her, aside from the internal campaign dynamics. Therefore, for simplification, we assume a perfect correlation between endorsement and vote for López, a hypothesis that presumably slightly overestimates her final support. We do not model deviations for López because we consider that, given the nature of her candidacy, they will be of second order.
“The key really lies in to what extent the deviation between endorsements and votes materializes for Maroto”
Therefore, the key is really in how much the deviation between endorsements and votes materializes for Maroto. We start from the fact that Maroto obtained 1,376 endorsements and López 1,028, and that the membership census with voting rights is 5,485. To make projections, I assume, conservatively, that turnout will be the same as in 2019, when there were competitive primaries for the last time in Madrid’s PSOE, which stood at 50.5%. Of course, turnout could be lower (we are in July and 2019’s primaries were in March) or higher (in these elections, the apparatus is weaker than then and the alternative appears more competitive), but it is not possible to quantify these effects. In any case, with a turnout of 50.5%, the vast majority of voters would already have endorsed one of the two candidates.
With that turnout percentage, the number of voters would be 2,770. If we assume that everyone who endorsed will vote (which will not be the case in reality, but is necessary methodologically as a starting point), i.e., 2,404 (1,376 + 1,028), the gap corresponds to voters who did not endorse anyone, that is, only 366 (2,770 – 2,404), which already shows how open the final result is.
Let us now assume, for simplicity, that all López endorsements translate into votes for her candidacy (which in reality will not be exactly so, since there will always be people who cannot go to vote for various reasons, but we consider this statistically negligible and, in any case, it would be offset by an equivalent effect in the case of Maroto), and that between 5% and 20% of Maroto’s endorsements will not translate into votes.
To this result one must add the estimate of votes not stemming from endorsements, as well as estimate whether the endorsements for Maroto that do not translate into votes go entirely to blank or abstention, or whether some will translate into votes for López, which is more reasonable. Let us begin with the latter, with three assumptions for each of the deviation scenarios (5%, 10%, 15% and 20%): no transfer and transfers of 25% and 50%.
That is, with deviations in Maroto’s endorsements of only 5% or 10%, even with transfers of 50% in López’s favor, the gap between Maroto and López remains substantial: 1,238 versus 1,097 (ceteris paribus: we have not yet projected non-endorsed voters). But, if the deviation from endorsements reaches 15% or 20%, the gap becomes minimal, and even in the last row López overtakes Maroto (1,166 votes to 1,101, ceteris paribus).
“If the deviation from endorsements reaches 15% or 20%, the margin is minimal”
Now look at the projections of voters who have not endorsed anyone, which, according to our initial assumption, are only 366. We assume, for simplicity, that the 366 are split between Maroto and López with no blank votes. If we assume these votes are distributed in the same proportion as the endorsement percentages (57% for Maroto and 43% for López), the total vote result would be trivial and would not differ from that of the endorsements.
The truly interesting projections must respond to other assumptions, in line with the possible deviations from the endorsements granted to Maroto. In this first table we show the projections assuming that deviations in endorsements do not translate into any transfer of votes in López’s favor.
We see here that, if 20% of Maroto’s endorsements do not translate into votes for her candidacy, even if they do not go to López, her vote percentage among voters who did not endorse anyone falls to 46% and the gap with López is minimal (1,269 to 1,226).
Now see what happens if, in addition, López gains new votes not only from those who did not endorse, but also from some of those who had endorsed Maroto, the most realistic scenario, as noted above.
That is, López, with a 15% deviation in Maroto’s endorsements and capturing 50% of them, is already very close to the former minister, just 29 votes behind, and would surpass her if she converts at least a quarter of the 20% of Maroto’s endorsements (69 votes) and gains at least half of the votes from those who did not endorse anyone (183), as a reference threshold. In other words, she would need 252 more votes in total, added to her endorsements, which we treat as starting votes.
Qualitative analysis
The qualitative analysis based on PSOE primary experience is more favorable to López than the quantitative simulation, as it indicates that in several of the most relevant precedents the candidate associated with the party machinery loses, particularly when this political force faces complex scenarios, provided that the outsider has a sufficient degree of knowledge, track record, and intellectual and communicative qualities, as is the case here.
“Being seen as the machinery’s candidate is almost always a negative factor, which helps the rival to portray himself as the ‘candidate of the base’.”
In fact, being seen as the machinery’s candidate is almost always a negative factor, which helps the rival to portray themselves as the “candidate of the bases.” Maroto is, moreover, a former minister, a status that has not proven to be an added value in the Aragonese and Andalusian elections.
The first PSOE primaries after the return to democracy were held in 1998, to designate the candidate for prime minister. Josep Borrell decisively defeated Almunia (55% to 45%), then secretary-general of the party during a transitional moment after Felipe González’s departure. That same year, in Madrid’s PSOE primaries, Fernando Morán narrowly defeated Joaquín Leguina, with the former seen as Borrell’s candidate and the latter considered the preferred choice of the secretary-general of the Madrid Socialist Federation, Jaime Lissavetzky, and Almunia himself.
In 2010, Tomás Gómez, secretary-general of the then Madrid Socialist Party, defeated Trinidad Jiménez, the federal leadership’s candidate, by 52% to 48%. In the 2014 PSOE primaries for secretary-general, the dynamic between machinery and outsider was not as clear, since Eduardo Madina was secretary-general of the Socialist Parliamentary Group and enjoyed the support of the outgoing leader, Alfredo Pérez Rubalcaba, while Pedro Sánchez, a Madrid deputy, had the backing of the powerful Andalusian federation then led by Susana Díaz. In 2017, there was a classic clash between machinery and outsider, with Sánchez’s decisive victory over Díaz.
“Enma López has a serious chance of pulling off a surprise in view of the likely loss of votes relative to Maroto’s endorsements”
In conclusion, Enma López has a serious chance of pulling off a surprise in light of the probable loss of votes relative to Maroto’s endorsements, a loss that some party leaders and militants feel obliged to publicly back as long as that loss is substantial—not less than 20%—and López manages to project in the internal campaign the momentum of having secured the endorsements —not everyone had taken that for granted— and the epic narrative of renewal and outsider against the status quo and the machinery, as in the cited experiences. Although the outcome of competitive primaries almost always tends to be close, given the mobilization and pressure capacity of the machinery, in my view Enma López has ample personal and political qualities to achieve it or to come very close, which in itself is a success.
