**PAN leads trader expectations for second place in Mexico’s 2027 Chamber of Deputies election due to its consistent edge in recent national polling over other opposition parties.** Surveys from late August through September 2026 show PAN at 11–18% support, ahead of PRI (8–14%) and MC (9–12%), while Morena holds a wide lead at 33–41%. The opposition remains fragmented after PAN ended its prior alliance with PRI and chose to contest the June 6, 2027, vote independently; PRI and MC have also rejected unified fronts. PAN’s stronger performance in several state capitals it currently governs and lower rejection rates compared with PRI further support its positioning. Traders view these polling trends and structural splits as the main drivers keeping PAN probabilities elevated, with limited recent catalysts to alter the ranking.