The closed primary format, approved by PS members in July over Olivier Faure’s preferred open approach, restricts voting to party adherents and allied groups like Place Publique, concentrating influence among established networks. Raphaël Glucksmann enters as the leading contender following his Place Publique role and cross-party visibility, leaving a fragmented contest for second place among Faure, Ségolène Royal, Philippe Brun, and Jérôme Guedj. Recent candidate declarations through early September, including Royal’s confirmation of sufficient sponsorships and Faure’s late-August announcement, have kept probabilities tightly grouped near 40 percent for several contenders. September debates and any shifts in internal endorsements or turnout mobilization could widen gaps before the October 9–10 first round.