Today is the biggest day of all in the ongoing Assembly elections. All of Tamil Nadu, Kerala and Puducherry are voting today in a single phase. Polling will come to an end in Assam after the polling in last 40 constituencies on Tuesday. In West Bengal, 31 assembly seats are voting today in the third phase with five more phases to go in the high octane election. In all the four states, the fight is largely bi-polar. In West Bengal it's an ascendant BJP that is trying to wrest power from a formidable Trinamool. In Kerala, it's a contest between the Left Front and the Congress-led UDF. Assam contest is squarely between the BJP and the Congress alliances. In Tamil Nadu, the AIADMK and DMK alliances are battling it out in Tamil Nadu, while Kamal Haasan’s Makkal Needhi Maiam is looking to establish itself as a serious political force. A total of 475 Assembly constituencies are voting today across four states and a union territory