Mannargudi is an important constituency in Thiruvarur district, known for its political significance and strong association with the DMK. In the 2021 Assembly elections, DMK’s Dr. T. R. B. Rajaa won the seat for the third consecutive time with 87,172 votes. He defeated AIADMK’s Siva. Rajamanickam, who secured 49,779 votes. The margin of victory was 37,393 votes. In the 2016 Assembly elections, DMK’s Dr. T. R. B. Rajaa won with 91,137 votes, defeating AIADMK’s S. Kamaraj, who received 81,200 votes. The margin of victory was 9,937 votes. In the 2011 Assembly elections, DMK’s Dr. T. R. B. Rajaa won the seat with 81,320 votes, defeating AIADMK’s Siva. Rajamanickam, who secured 77,338 votes. The margin of victory was a tight 3,982 votes.