The Tamilaga Vettri Kazhagam (TVK) has significantly impacted Tamil Nadu's political landscape in the 2026 Assembly elections, challenging the long-standing bipolar system. Analysis of 134 constituencies where the TVK, DMK, and AIADMK directly competed reveals that the AIADMK has lost substantial core voter support to the TVK, posing an existential threat to the party. In contrast, the DMK has largely maintained its voter base, although it experienced its lowest vote share in the Greater Chennai region. A strong negative correlation was observed between AIADMK and TVK vote shares, particularly in the Central and South regions, indicating that as AIADMK's votes declined, TVK's increased. This pattern was less evident between the DMK and TVK, except in Greater Chennai. While the AIADMK is seeing its lowest vote shares, the DMK experienced a larger overall vote swing since 2021, primarily due to losing floating voters to the TVK, whereas the AIADMK lost a smaller vote share but a greater fraction of its core support.