Overview
- The government has set a snap general election for 29 November and, as of 21 October, parties are finalizing lists with the PSOE and Frente Amplio running joint 'Senado de Progreso' lists while the PP says it is negotiating tactical arrangements with Vox.
- Private polls from firms such as GAD3, Sigma Dos and 40dB project a PP‑Vox advantage while the public CIS barometer gives the PSOE a lead, creating two competing narratives about momentum and turnout.
- Spain’s open, majoritarian Senate system lets voters pick individual candidates, so pre‑electoral coalitions or tactical withdrawals can sharply change results by concentrating votes on one list.
- Electoral simulations show that if Vox withdraws in 13 or 19 provinces and its voters back the PP, the probability that the right regains a Senate majority rises to roughly 75% or 90% respectively, but securing a three‑fifths majority for institutional appointments remains uncertain.
- Control of the Senate matters beyond politics because a three‑fifths chamber majority would allow appointment of Constitutional Court magistrates, CGPJ members and the Defender of the People, which could reshape judicial oversight and affect policy areas like housing and accountability.