As Tamil Nadu approaches the 2026 Assembly elections, insights from past exit polls, particularly the 2021 elections, reveal important trends. In 2021, most exit polls correctly forecasted a victory for the Dravida Munnetra Kazhagam (DMK)-led alliance, which won 159 seats in the 234-member Assembly, ending the AIADMK's decade-long rule. However, these polls significantly overestimated the margin of victory, with predictions suggesting the DMK would secure between 160 and 190+ seats. In reality, the AIADMK performed better than anticipated, winning 75 seats. This discrepancy illustrates a recurring pattern in Tamil Nadu's electoral history, where exit polls tend to reflect broad voter sentiment but often miss local complexities. Factors such as urban-rural divides, caste dynamics, and late shifts in voter preferences can significantly affect outcomes. As the 2026 elections approach, the lessons from 2021 highlight the importance of viewing exit polls as trend indicators rather than precise forecasts, particularly in the context of another competitive race between the DMK-led alliance and the AIADMK.