Morena and PAN lead trader pricing for the Mexico City Congress election winner amid a fragmented opposition field ahead of the 2027 vote. National and local polling shows Morena holding roughly 35-43% preference, benefiting from its control of most alcaldías and alignment with the federal administration, while PAN registers 11-24% and benefits from traditional strongholds in several boroughs. PRI and Movimiento Ciudadano trail further back, with the latter confirming it will run independently after rejecting coalition talks; PAN-PRI alliance negotiations remain unresolved. The formal electoral process opened in September 2026, with pre-campaigns scheduled for early 2027, leaving room for shifts from candidate selection, turnout patterns, and any late coalition agreements.