The Trinamool Congress started off its campaign in West Bengal brimming with confidence. Against all odds, they had completed their five-year tenure with far more ease than most of their critics had predicted when they assumed office in 2011.

Adding to the sense of achievement was that this was the first non-Left front West Bengal government in three and a half decades.

However, as the campaign progressed, the party started to get a bit nervous. The Left-Congress alliance might have been an odd pair, but driven largely by the fear of what another five years of Trinamool rule would do to them, they actually managed to work rather well on the ground. Add to that the punishing six-phase election that the Election Commission had mapped out meant that this was the state’s cleanest, least violent election in two generations. Trinamool lost the “home advantage” of being the incumbent party – one that every incumbent, be it the Congress or the Communist Party of India (Marxist), had (unfairly) enjoyed in the state before.

Of course, all’s well that ends well. The Trinamool now looks to win a two-thirds majority and, at the time of writing this, was leading/had won in a massive 217 seats out of the 294-strong West Bengal Assembly.

As the green abeer settles down outside the Trinamool office at Harish Chatterjee Street, here are five reasons, in no particular order, as to why Mamata Banerjee was able to engineer such a comprehensive win in West Bengal.

1. Development

Yes, it’s a much abused, near meaningless word in Indian politics today but in the past five years West Bengal did see some meaningful improvement in public works, infrastructure and government programmes. None of this was a paradigm shift of any sort and the Trinamool wasn’t able to leverage it as well as it would have liked in its public messaging – but the change in the lives of the common Bengali was significant enough to ensure a groundswell of support for Mamata Banerjee.

Take the National Rural Employment Guarantee Act, for example. Throughout Mamata’s rule, West Bengal has leveraged the scheme fully, with the state administration making sure that large numbers of rural Bengalis are able to benefit from it. In the past four years, West Bengal has easily been one of the top states in terms of the labour generated from the NREGA. In comparison to Gujarat, for example, West Bengal has utilised 9.6X the number of NREGA person days from 2012-13 to 2015-16. For Maharashtra, that ratio stands at 3.2 – it is 3.1 for Bihar.

More of the basics: toilets. From 2011 to 2015, West Bengal built the second largest number of toilets for individual households in rural areas amongst all other states. It is also the state with the second highest number of villages declared free of open defecation. A fifth of all Indian villages declared free of open defecation are in West Bengal, second only to Himachal Pradesh. This toilet building is replicated even in urban areas such as Kolkata.

Rural connectivity has seen a visible jump, with even small villages now having tarmac-surfaced lanes leading up to them. Even the Adivasi-dominated, highly underdeveloped area of Junglemahal now has excellent metalled roads.

Banerjee has also kept on eye on education. Sabuj Sathi, a scheme to distribute cycles to students from classes 9 to 12 has been very popular across rural West Bengal, as has Kanyashree, a scholarship scheme for economically disadvantaged girls. The scholarship consists of an annual stipend of Rs 750 and a one-time payment of Rs 25,000 if the students continues their studies up the age of 18 – a measure aimed at preventing girls from dropping out and lowering the rates of child marriage.

2. Social engineering

The Left’s 34-year rule was based on a strong agenda of social justice. This, most significantly, included land reforms where sharecroppers were given right to the land they tilled – something that the Congress, a party dominated by land owners, had bitterly opposed when it was earlier in power.

That, combined with a near-army of communist cadre, meant that the actual Left leadership had never needed to appeal to social identity to win elections. The Trinamool, of course, never had that advantage, so it used subaltern caste identity to try and combat the CPI(M)’s cadre strength. This included appeals to the large Matua sect, consisting of Bengal’s largest Dalit caste, the Namashudras, as well as the courting of Muslim Bengalis. Rural Muslim Bengalis, almost all cultivators, had been a strong support base for the CPI(M) but were greatly alienated by incidents such as the violent farmland grab in Nandigram in 2007.

This appeal to identity is also in all probability responsible for the rise of the Bharatiya Janata Party, which has done surprisingly well in this election, signifying for the first time, the emergence of Hindutva in Bengal. At the time of writing this, it had managed to get a vote share of 10.3% – a figure which won’t break the bank but given the party’s perpetual minnow status in West Bengal isn’t a bad performance at all.

3. Steady left-wing populism

The loss in 2011 might have been a loss for the Communists but a good case can be made for it not being a loss for leftism in West Bengal. If the Trinamool has any ideology that keeps in together – apart from the cult of Mamata Banerjee, that is – it is left-wing populism.

Banerjee has kept up a constant image of being aggressively pro poor – a core part of which is her land policy. The Trinamool came to power based on rural discontent with the Left’s farmland acquisition for industry – a fact that it hasn’t forgotten in its five years in power. In 2012, Banerjee scrapped the state’s Special Economic Zone policy. She also resisted pressure to repeal the land ceiling act – a stubbornness that, reports claim, is one of the reasons for the bitter Anandabazar Patrika Group–Trinamool feud. And, of course, she did not repeat the CPI(M)’s mistakes with farmland acquisition. In fact, the first decision Banerjee’s cabinet took after coming to power in 2011 was to return land acquired for a Tata Nano plant back to the farmers in Singur.

4. Increased social sector spending

If someone had to list the core skill of Mamata Banerjee, they's probably put down punchy oratory and street doughtiness – after all, she’s been a mass Bengali politician battling the ruling Left all her life. Things people won’t list are fiscal consolidation and administrative competence. Yet, the Banerjee government has done surprisingly well at exactly that, doubling tax revenue in West Bengal in the past five years.

This, in turn, has meant more money for Banerjee to fund her left-wing populism. Social sector spending – by far the primary reason for the Trinamool’s sweep today – has tripled in the past four years.

Banerjee has also shored up her finances by ignoring the urban organised sector – a core support base for the CPI(M), spending that money on rural West Bengal instead. Dearness Allowance for state government employees has lagged those for Union government employees by a large margin and Banerjee has only announced sporadic, small hikes.

5. The Left-Congress alliance was too little, too late

The 2014 Lok Sabha polls was in some ways an even bigger jolt for the CPI(M) in Bengal than the 2011 Assembly election. In it, the CPI(M) slipped to third place in numbers of seats, winning 2, behind the 4 won by the Congress. The CPI(M) and the Bharatiya Janata Party got the same number of seats – an embarrassing proposition for the Left, which had ruled the state for three and a half decades. But there was a ray of hope: the combined vote of the Congress and the Left – the state’s two main opposition parties – was 39.6%, just a shade lower than the Trinamool’s 39.8%.

To anyone with a smidgen of political sense, a Left-Congress alliance to take on the Trinamool was the obvious need of the hour. Indeed, the Left and Congress workers on the ground, at the receiving end of bullying from triumphant Trinamool workers, were crying out for an alliance. Unfortunately, both the CPI(M) and the Congress are parties which swear by the purest form of High Command culture. In the CPI(M), the politburo is the highest decision-making body – staffed by many apparatchiks who would be unable to win even a gram panchayat election in West Bengal. Yet, they dictate orders to mass leaders. In 1996, a person as experienced as Jyoti Basu, India’s longest serving chief minister, had to bow to the decision of the politburo and reject the position of Prime Minister – a “historical blunder”, in Basu’s own words, that marked the beginning of the end of the party.

And, of course, in the Congress, you have a similarly odd party structure where Delhi leaders, completely out of touch with West Bengal, take decisions over state leaders such as Adhir Chowdhury.

This top-heavy decision making from distant Delhi meant that the Left-Congress alliance, an obvious political choice, became a Gordian knot as both High Commands hemmed and hawed. The Congress was worried about impact in Kerala (where it is fighting the Communists) and parts of the CPI(M) High Command were, surreally, discussing the finer points of communist philosophy, given that in theory the Congress was a “bourgeoisie-landlord” party.

In the end, faced with a cadre revolt, both High Commands agreed to the joat, alliance, a month before the election. But it was too little and too late. Even at this crucial stage, both parties were shy of calling it an “alliance”, preferring weasel words like “tactical arrangement”. And apart form this last minute “tactical arrangement”, there was nothing else: a plan for governance, in case the joat did happen to win, wasn’t even discussed.

This was a poor signal to send to the voter. The joat was contesting the elections but literally had no agenda beyond their own personal one of defeating Banerjee. That Bengalis comprehensively chose the Trinamool to head the government over an eleventh hour, agenda-less “tactical arrangement” is no surprise.