Morena leads trader assessments for the June 2027 Mexican legislative election at 84.4% implied probability, reflecting its consistent polling advantage of 35-41% in national surveys ahead of the contest for all 500 Chamber of Deputies seats. Recent measurements from late September show the party holding a wide margin over PAN at 11-17%, with PRI, Movimiento Ciudadano, and smaller options trailing further behind. The electoral process formally opened in September 2026, coinciding with ongoing coalition dynamics between Morena and its allies PVEM and PT, alongside a fragmented opposition that has yet to consolidate into a unified national front. Public polling also highlights divided expectations on whether the ruling bloc will retain a legislative majority, though individual party preferences continue to favor Morena as the largest single force.