West Bengal polls: How BJP became Trinamool Congress' main challenger

As the Left and Congress declined, BJP has consolidated anti-TMC votes in the last decade, emerging as the main challenger to Mamata Banerjee and TMC

West Bengal heads into Assembly election in two phases on April 23 and April 29. Ahead of polls, the central question is no longer whether the Bharatiya Janata Party (BJP) is a contender, but how it rose so quickly to become the ruling Trinamool Congress’ (TMC) principal challenger.

 

Over the past decade, the state’s political landscape has undergone a fundamental shift. What was once a multi-cornered contest dominated by the Left-Congress axis has steadily transformed into a bipolar contest between the TMC and the BJP. While the BJP’s rise has been sharp, the TMC has simultaneously retained and deepened its electoral dominance in the last 15 years.

 

 

How limited was BJP’s presence after the Left’s exit in 2011?

 

The 2011 Assembly election marked a turning point in West Bengal with the end of the Left Front’s 34-year rule. But for the BJP, it highlighted how marginal the party still was.

 

It secured 4.06 per cent of the vote and did not win any seats. The contest was dominated by Mamata Banerjee-led TMC, which formed the government with 184 seats and nearly 39 per cent vote share. The Left Front, despite losing power, polled over 40 per cent, while Congress retained a secondary presence.

 

At this stage, Bengal’s politics remained structured around the TMC versus Left-Congress framework, with the BJP outside this core contest.   

 

What changed between 2011 and 2016?

 

The BJP’s first measurable expansion came during the 2016 Assembly election. Its vote share rose to 10.16 per cent, and it won three seats.

 

While still not electorally decisive, this shift signalled the beginning of a new alignment. The BJP started attracting voters dissatisfied with the TMC, particularly in regions where the Left and Congress were weakening.

 

This shift became more visible in parliamentary polls. In 2014, the BJP made gains in vote share and won two Lok Sabha seats. By 2019, it had surged to 18 seats with 40 per cent vote share, emerging as the principal opposition party in the state. In the 2024 Lok Sabha elections, the BJP won 12 seats with a vote share of 39.1 per cent.

 

What was behind the rapid growth of BJP in 2021?

 

The most significant change came in the 2021 Assembly election. The BJP’s vote share rose to 37.97 per cent, up from just over 10 per cent in 2016, and it won 77 seats.

 

However, this growth was not driven solely by new voter mobilisation. A large part came from the decline of the Left Front and Congress.

 

The Left, which had polled over 40 per cent in 2011, saw its base shrink steadily. Losses for Congress followed too. As these parties declined, a significant section of their anti-TMC voters gravitated towards the BJP.

 

What areas witnessed the biggest changes?

 

The BJP’s gains were not uniform across the state. Districts such as Purba Medinipur, Cooch Behar, Purulia, Bankura, Darjeeling and Nadia saw particularly strong growth between 2016 and 2021, becoming key centres of expansion.

 

At the constituency level, the changes were even more pronounced. Seats including Bhagabanpur, Ranaghat Uttar Purba, Santipur, Ranaghat Uttar Paschim, Bagdah, Moyna and Pursurah recorded steep rises in BJP vote share, in several cases exceeding 40 percentage points.

 

These shifts indicate that the BJP’s growth was not gradual everywhere. In several pockets, it involved rapid consolidation within a single election cycle. 

 

Why did BJP fall short of power in 2021?

 

Despite its gains, the BJP fell short of power in 2021. The TMC secured around 48.02 per cent of the vote and won 213 seats.

 

The BJP’s growth came largely at the expense of the Left and Congress, rather than directly eroding the TMC’s core support base.

 

In contrast, the TMC retained broad support across regions and converted its vote share into a significantly higher proportion of seats.

 

What has changed in Bengal’s political structure?

 

Between 2011 and now, West Bengal has shifted from a multi-cornered contest to a bipolar one. A decade after being on the margins, the BJP is now firmly in the contest, but dislodging the TMC remains a far steeper challenge than becoming its main rival.