The electoral dynamics in Assam, Kerala, TN, West Bengal | Number Theory

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Updated on: Mar 16, 2026, 08:22:02 IST

By Nishant Ranjan, Abhishek Jha, Roshan Kishore

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Elections for the four states of Assam, Kerala, West Bengal, and Tamil Nadu, and the Union territory of Puducherry were announced on Sunday. Polling will be a one-day affair in Kerala, Tamil Nadu, Assam and Puducherry, and a two-phased one in West Bengal. Counting of votes will take place on May 4. Here are four charts which explain why these elections matter and what will drive them.

A massive crowd gathers to attend a political rally in Tamil Nadu. (ANI)

The electoral dynamics in Assam, Kerala, TN, West Bengal

Incumbents are eying their fourth win in West Bengal, third in Assam and Kerala, and second in Tamil Nadu
The Trinamool Congress (TMC) has been in power in West Bengal since 2011, the Bharatiya Janata Party (BJP) and the Communist Party of India (Marxist) or CPI(M)-led Left Democratic Front (LDF) in Assam and Kerala, respectively, since 2016, and Dravida Munnetra Kazhagam (DMK) in Tamil Nadu since 2021. If one were to read assembly and Lok Sabha election results together, the TMC has not lost an election in the state since 2009, the BJP since 2014 in Assam and the DMK since 2019 in Tamil Nadu. The LDF in Kerala, on the other hand, has failed to replicate its 2016 and 2021 assembly elections victories in the 2019 and 2024 Lok Sabha elections. If the incumbents do manage to retain power, they will level or come close to the historical record in Assam, Tamil Nadu, and West Bengal; and achieve an unprecedented feat in Kerala.
Three out of seven non-Congress, non-BJP chief ministers in the country will be testing their fate in this election cycle
Out of the 18 large states which have 10 or more Lok Sabha seats, nine have chief ministers from the BJP. Only two have Congress chief ministers while seven – Andhra Pradesh, Bihar, Jharkhand, West Bengal, Tamil Nadu, Kerala, and Punjab – are ruled by non-BJP, non-Congress chief ministers. Of these, the chief ministers of Bihar and Andhra are from parties that are allied with the BJP. That means three out of the only five large states with a non-Congress, non-BJP chief minister will be seeking a fresh mandate in this election cycle (to be sure, the DMK is a long-standing ally of the Congress, but is the senior partner in the alliance). While the BJP is the primary opposition party in West Bengal, it is the Congress which is hoping to end the LDF’s victory run in Kerala. In Tamil Nadu, it looks like a straight contest between the DMK led alliance and a National Democratic Alliance led by the All India Dravida Munnetra Kazhagam (AIADMK). The stakes are the highest for the CPI (M) in Kerala as an election loss there will be a first when communists would not be in power in any Indian state; big or small, since 1977.
In 2021, LDF exploited the first-past-the-post system the best in Kerala, BJP’s gains in Assam were the lowest
In India’s first-past-the-post electoral system there is always an X factor in how a party or alliance translates popular support (best measured by vote share) into legislative representation (best measured by seat share). A good way to measure a party’s efficacy in exploiting the vagaries of the FPTP system is to compare its seat share to vote share ratio in a particular election. In the 2021 election cycle in these states, the CPI (M)-led LDF had the highest seat share to vote share ratio in Kerala while this number was the lowest for the BJP-led alliance in Assam. Even a change in this efficacy without a large variation in popular support could lead to a large change in electoral fortunes of these parties. For the record, Assam has seen a delimitation after the 2021 elections and West Bengal is still in the process of adjudication on about six million voters who have been issued notices under the Special Intensive Revision (SIR) exercise.
Demographically, there is a significant variation between these states
Religious and caste demographics are important drivers of electoral fortunes in India. The four states going to polls are a varied lot . Assam has the highest share of Muslims in the state population among all major states in India followed by West Bengal and Kerala. Muslims constitute a share of 34.2%, 27%, and 26.6% of the state’s population in Assam, West Bengal, and Kerala, respectively, according to the Census of India 2011 data. However, what needs to be kept in mind that Muslim population in Assam is much more skewed at the constituency-level than in the other states. When it comes to caste composition, Tamil Nadu leads in share of Other Backward Class (OBC) population by a distance where they account for more than two-thirds of the population compared to the national average of 42%.

ABOUT THE AUTHOR
Nishant Ranjan
Nishant Ranjan has been working as a data journalist with Hindustan Times since 2023. In this short period, he has established a niche for creating original datasets and utilising them to produce journalistic work that pushes the boundaries of journalism. The list of datasets and stories done by him include the following: a dataset of all 717 chief ministers India has had since 1952, a dataset of all 3,350 members of India’s council of ministers, a dataset of all 190 deputy chief ministers in India and a dataset of all 279 Supreme Court judges in India (1950-2025). He has also profiled each elected Muslim MLA/MP since 1952. He is a mining engineer by training who decided to pursue a Master's in Development Studies from TISS after working in a coal mine for 10 months. He also worked as a research associate at the Centre for Policy Research, researching local governance in India. He also has a keen interest in analyzing electoral politics and political executives in India.Read More
ABOUT THE AUTHOR
Roshan Kishore
Roshan Kishore is the Data and Political Economy Editor at Hindustan Times. He heads the newsroom's data journalism team, which produces Number Theory, a daily data-driven feature for the print edition and the HT app. Number Theory uses data analysis and story-telling based on it to add value to the newsroom’s daily coverage by putting stories in a larger context on a range of issues, including politics, macroeconomy, markets, global affairs and climate. Under his leadership HT’s data journalism work has established itself as a niche product in Indian journalism and pushed the boundaries of marrying academic rigour with news sense and speed. Along with writing and editing data stories, he has also been writing a weekly political economy column called Terms of Trade for HT Premium. A trained economist with an MPhil degree from Jawaharlal Nehru University, Kishore has also been a visiting fellow at the Centre for Advanced Studies of India (CASI) at the University of Pennsylvania. Along with his journalistic work, his writings have also appeared in journals such as the Economic and Political Weekly and working papers for CASI and UNESCAP.Read More