TCPD Columns

Battlegrounds: Analyzing national and state level parties’ performances in Assam and West Bengal in the 21st century

Aishwarya Sunaad and Shoaib Mirza

4 May 2021 | 4 min read

The 2021 assembly elections attracted much discussion across the country, especially with the Bharatiya Janata Party (BJP) trying to expand its foothold in unchartered territories against combative regional satraps in east and south India.  In the southern states of Tamil Nadu and Kerala particularly, and also in West Bengal, the regional or state level parties have reigned supreme while in Assam, the BJP swept the elections. In this light, this article will look at the performance of state parties and national parties across these five states since 2001 and highlight interesting trends and help map the political trajectories of these regions.

In the first piece of this series, we focus on the states of  West Bengal and Assam, and in the following piece on TCPD Columns, we will look at the southern states. 

To begin with, the data can be obtained from TCPD’s open source political data collation and organisation tool Lok Dhaba. Upon navigating to the Browse/Download Data page, data for the required states can be downloaded across election years. 

Using the Data 

In the dataset, the following selections should be made to obtain the required filtered data for analysis: 

  • Poll No. = 0 (1 means a bye-poll)
  • Position = 1, as we are interested in the candidates who won (1,2,3…denote the positions secured by candidates in the elections)

The Politics of West Bengal 

The politics of West Bengal has been dominated by the Left Front, led by the Communist Party of India-Marxist (CPM), and the Trinamool Congress (AITC) in the last two decades. The Left Front, which includes the CPM, the Communist Party of India (CPI), the All India Forward Bloc (AIFB), and the Revolutionary Socialist Party (RSP) among others, ruled Bengal for over three decades from 1977 to 2011. They were ultimately defeated by Mamata Banerjee’s AITC in 2011, a break-away faction of the Indian National Congress (INC) formed in the late 1990’s. The national parties, the Congress and the BJP, have held minimal, but varying influence on the state’s politics over the last two decades. However, this changed in 2021 with the elections revolving around the political competition between the incumbent AITC and the challenger BJP. Table 1 below shows the changes in seats won by these parties over the last five elections. 

Table 1: Seats won by national and major state level parties in West Bengal from 2001-2021

Table 1.1: Seats won by other state level parties and independent candidates in West Bengal from 2001-2021

The same data is plotted in the below graph. 

Figure 1: Share of national and state level parties in West Bengal from 2001-2021

What’s happening 

An overview of the data shows that in the first decade of the century, the Left Front dominated state politics. Among the two most influential parties in the state, while the CPM won 143 out of the 211 seats it contested, the AITC won only 60 out of the 226 seats it contested. 

In the subsequent years, we see that the CPM’s seat share drastically declined in 2011––to a mere 40 out of the 213 seats it contested–– from its tally of 176 seats out of 212 in 2006. This sharp decline corresponds with the rise of  Mamata Banerjee’s AITC, rising to power with 184 seats out of tota 226 contested seats, nearly four times that of the CPM’s in the same year. This marked the end of the CPM’s 33-year long rule in West Bengal.  Since its victory in 2011, the AITC has gone on to win every assembly election, including the one in 2021 where it bagged a massive 213 out of the 288 seats it contested. 

During this period, the share of seats won by the national parties has been dismal. With the rise of the AITC, much of the Congress vote share was transferred to Mamata Banerjee’s party. In 2001, we see that of the two major national parties, the INC won 26 seats out of the 60 it contested, whereas the BJP won none. While the Congress only won 21 out of the 262 seats it contested in 2006, it improved its tally in 2011 and 2016 by aligning with the AITC and CPM respectively. 

The BJP, on the other hand, could not win a single seat in the state assembly from 2001 to 2011, it won three seats in the 2016 assembly elections. However, it made major inroads into the state in the subsequent years, winning 77 out of the 291 seats it contested. The BJP’s rise corresponds to the complete decimation of the Left Front and the Congress in the state, which failed to win a single seat in the 2021 elections.  

Abiding Winners and Changing Tides

From the above data, it is clearly visible that in West Bengal, from the beginning of the 21st century, it is the regional parties that have dominated politics. It largely follows the trends of Bengal politics since the 1970s where national parties have failed to wrest the state from regional outfits. 

Of the two national parties, while the INC’s performance has swayed from being dismal to a marginally effective smaller partner in a coalition, the 2021 elections dealt a huge blow to the national party. Unable to win a single seat, the party lost its last bastions of Malda and Murshidabad in the state, with politics revolving round the AITC and BJP in the state now. With its remarkable leap in its performance, the BJP has replaced the Congress as the major national party at the fore of West Bengal’s politics. 

In terms of the other state-level parties, significantly the AIFB and the RSP that formed the Left Front, their influence has waned over the years with the rise of the AITC since 2011.  

On Assam 

Assam’s politics was dominated by the Congress party since the 1950s. Barring minor intervals of President’s Rule or governments formed by regional parties such as the Asom Gana Parishad (AGP), Janata Party (JP) and Communist Party of India (CPI), mostly in coalition, the north-eastern state was a Congress fortress. However, the Congress was trumped by the BJP in 2016, especially following the pro-BJP wave across India since Narendra Modi’s rise onto the national scene in 2014.  The following data shows the INC’s and BJP’s trajectory along with that of Assam’s state-level parties’ from 2001 to 2021. 

Table 2 reflects the performance from 2001 to 2021 of the two national parties––INC and BJP––along with Assam’s state-level parties––Asom Gana Parishad (AGP), All India United Democratic Front (AIUDF) and the Bodoland People’s Front (BOPF)–– which have played a significant role in the state’s politics. 

Table 2: Seats won by national and major state level parties in Assam from 2001-2021

Table 2.1: Seats won by other state level parties and independent candidates in West Bengal from 2001-2021

The above data is plotted in the graph below. 

Figure 2: Share of national and state level parties in Assam from 2001-2021

What’s in the numbers?

We see that there are fluctuations in the performance of the INC in the first decade of our analysis. From 71 out of 126 seats in 2001, the party won a lesser number of seats in 2006––53 out of 120 contested. In 2011, the Congress won a mammoth majority in 2011, bagging 78 out of the 126 seats it contested. For the same period, we see that the BJP’s performance in Assam is below par winning 8 out of 46 seats it contested in 2001,10 out of 125 in 2006, and 5 out of 120 in 2011.

In the 2016 elections, however, things changed drastically. While the Congress could only win 26 out of the 122 seats it contested, the BJP wrested Assam by winning 60 out of the 89 seats it contested. It crossed the half-way mark convincingly with its coalition partners the AGP and the BOPF. In the 2021 elections, the BJP continued to outperform the Congress, winning 60 out of its 93 seats, while the Congress won a mere 29 out of its 95 seats.

Among the regional parties, the AGP has been a strong force in the state, especially since the days of the Assam movement of the 1980s. In the last decade, the AGP’s alliance with the BJP has yielded electoral benefits for the party, forming successive governments in 2016 and 2021. It won 14 out of 30 seats in 2016 and 9 out of 29 in 2021. 

The AIUDF and BOPF in comparison to the AGP are younger parties, having been formed in 2005. The AIUDF won 18 out of the 78 seats it contested in 2011, 13 out of 74 in 2016, and 16 out of 20 seats in 2021. The BOPF, on the other hand, has been a consistent regional outfit, winning 12 out of 29 seats it contested in 2011 and 12 out of 13 in 2016.   It must be noted that though the BOPF was in alliance with the BJP in 2016, it shifted allegiance to the Congress party in 2021 and was part of a coalition of 8 parties including the AIUDF, called the ‘Mahajot’. It only won 4 out of the 12 seats it contested. Another state-based party, the United People’s Party Liberal which was formed in 2015, won 6 out of 11 seats  in alliance with the BJP in 2021.

Conclusion: Battlegrounds

West Bengal 

From this data we see that in West Bengal, it is the regional parties that have influenced politics since 2001. One may choose to view this as a continuum of regional party dominance which began with the CPM holding power in the state from 1977 until its defeat in 2011. Post the diminishment of the CPM, we see that the dominant state party in West Bengal is the AITC led by Mamata Banerjee. Of the two national parties, both the Congress and the BJP held negligible influence in the state, except for 2011 and 2016 when the Congress contested  elections in alliance with the regional parties. However, what is notable is the steep rise of a national party like the BJP in the state’s politics. 

This is a crucial development because in the past two decades, it is the highest number of seats held by any national party in the state––the highest held by the INC was 44 in 2016 in coalition with the Left Front. It is more interesting because this figure was achieved by a party that held only 3 seats in the previous assembly election. This drastic rise indicates that West Bengal will  witness an increase in the influence of the BJP as it positions itself as a  formidable competitor to the AITC, with the possibility of the state experiencing a bipolar contest between the two in the coming years. 


Similar to its performance in West Bengal until 2021, the BJP’s performance in Assam till 2016 was dismal compared to that of the INC’s, with the BJP gathering only 5 seats in 2011 as opposed to the INC’s whopping 78––94% more seats than the BJP! Interestingly, just like in West Bengal, the BJP’s seat share increased drastically in Assam in just one electoral cycle, where it bagged 60 seats out of the 126 assembly seats in 2016, eventually forming the government for the first time in Assam in coalition with the AGP and BOPF. The BJP’s rise, therefore, has been at the cost of the steep decline of the Congress in the state. 

As per the vote shares of the regional and state-based parties, the AGP has witnessed a sharp deterioration in its popularity from its heydays of 1980s. However, smaller parties like the AIUDF and BOPF seem to perform well in the lesser number of seats they contest in coalitions with the national parties. Banking on its association with the BJP, which we see has risen in power in Assam rapidly, the new party, UPPL, may go on to become a major competitor to the existing state level parties over the coming years.

Going forward

To wrap up, we see that in both states, it is the BJP that was the principle disruptor in the last decade. Its rise as India’s new pan-national party can be witnessed beyond its traditional strongholds of north, central and western India. Most crucially, it has changed the political dynamics of both Assam and West Bengal by its sweeping rise across just one election cycle. While in West Bengal, it went on to become the national party with the largest seat-share in the last two decades, in Assam, it dethroned the Congress party that had held power in the state historically.

Acknowledgements: We thank Avishek Jha for feedback.

We encourage you to explore the data and use the incumbency tool. It is the product of a lot of time, hard work and love put in by TCPD staff members and our fabulous interns. If you spot errors and/or have any feedback, please get in touch with us at


“TCPD Individual Incumbency Dataset, 1962-current”. Trivedi Centre for Political Data, Ashoka University.

Ananay Agarwal, Prashasti Agarwal, Payoja Ahluwalia, Saloni Bhogale, Jenish Raj Bajracharya, Sudheendra Hangal, Samridhi Hooda, Mohit Kumar, Visvesha Murthi, Basim U Nissa, Vaibhav Parik, Ayaan Sagar, Niharika Tiwari and Gilles Verniers. 2021. “TCPD Individual Incumbency Dataset, 1962-current Codebook 1.0″, Trivedi Centre for Political Data, Ashoka University.