Was it the “Modi tsunami” or a “saffron wave”? The spectacular show by India's ruling Hindu nationalist Bharatiya Janata Party (BJP) in legislative assembly elections in the key political battleground of Uttar Pradesh reflects a consolidation of votes cutting across caste and religion affiliations. BJP has secured 312 of the total of 403 seats in the state -- a stunning mandate that even BJP President Amit Shah acknowledged as “unexpected”.

The result this year mirrors the 2014 parliamentary poll battle when BJP won 73 of the 80 Lok Sabha seats in UP. If analysts today are talking about a “Modi win” rather than “BJP win” in the state, there is a reason for this. Two and a half years ago, it was Modi and Modi alone on whom BJP had relied on heavily to sail through and the same was repeated in the assembly elections this time. Unlike its rivals, BJP went to polls in UP without projecting a chief ministerial candidate simply because no one has the charisma or vote-catching ability than that of Modi.

The election victories in UP, Uttarakhand and impressive gains in Manipur will be a big boost to BJP's bid for a pan-India embrace and strengthen Narendra Modi's position in the national political landscape, perk up the political narrative in the run-up to national elections in 2019.

Only three times in UP's history has a party crossed 300 seats -- in UP's first post-independent election in 1951, the 1977 election when the Janata Party swept to power and the 1980 election in which a resurgent Indira Gandhi propelled the party back to power.

A big slice of the credit for BJP's success in UP is due to its chief Amit Shah who crafted the election strategy of building a broad coalition of castes in UP. Interestingly, the party did not field a single Muslim candidate in the just-concluded elections in UP which has a sizable Muslim population.

Shah appointed BJP veteran Kesav Prasad Maurya as the head of the party's state unit and inducted Swami Prasad Maurya who defected from Bahujan Samaj Party (BSP) to not as part of efforts to changing the caste arithmetic which, along with Muslim votes, has traditionally played a key role in shaping the electoral outcome in the state. BJP's attempts were to rework the caste and religious fault lines. It took care not to irk any particular caste. In fact, the UP election was projected by Shah as a battle among Samajwadi Party's (SP) Muslim-Yadav (backward caste) support base and BSP's Jatavs (lowest rung in caste hierarchy) versus other Dalits which were supposed to vote for the saffron party.

Accordingly, BJP allocated around 150 seats to non-Yadav Other Backward Caste (OBCs) candidates in UP. This, along with its tie-ups with sub-regional parties like Apna Dal and Suheldev Bhartiya Samaj Party (SBSP) helped it consolidate non-Yadav backward caste groups like Patels, Kurmis and Rajbhars.

All political parties in UP resorted in some degree to attempts to polarise voters: SP and BSP sought to woo Muslim voters by asking them to vote “en bloc” for them. BSP gave nomination to nearly 100 Muslim candidates and a key reason behind SP's alliance with Congress was keeping an eye on votes from the minority community. Responding to rivals' strong push to win over Muslim votes, BJP too played Hindutva card during campaign through Modi's reference to “Kabristan” (graveyard) versus “Shamshan” (crematorium) remarks and Amit Shah's “Kasab” (Aamir Ajmal Kasab, the key man behind the November 2008 deadly terror attack in Mumbai).

Secondly, an important component of Shah's strategy for UP was that while BJP depended heavily on Modi's charisma, it was careful to ensure that local leaders are given due weight during campaigning keeping in view ground realities. This was a lesson that the party seemed to have learnt from its electoral debacle in assembly poll in Bihar a few years ago.

At the same time, Shah and BJP's other poll managers did not fall back just on local leaders and made full use of Modi. The prime minister was initially supposed to address around 10 rallies but ultimately spoke at around 30 rallies. Modi stayed put in his parliamentary constituency of Varanasi in UP overnight stay, something he didn't do even during the Lok Sabha polls. Both showed the high stakes Modi and BJP had in UP assembly elections, especially in eastern part of the state (including Varanasi) which has a total of 133 assembly seats.

Thirdly, in choosing candidates for UP poll, BJP appeared to believe that “at the end of the day it is the winnability of a candidate that matters.” The party welcomed candidates from other parties and it is estimated that about 100 seats were allocated to candidates who switched over from other parties because they were supposed to have better chances of winning than BJP's own candidates.

The elections in UP and the other states were the first major test of Modi's popularity in the wake of banning of high-denomination currency notes in November-December last year in a bid to cleanse the country's finance from the menace of black money. And Modi has passed the test with flying colours.

The demonetisation saw serpentine queues in front of banks and post offices as people rushed to return or exchange their old notes for several weeks. There was a perception that ordinary people were angered for having to stand for long hours in queues in banks and post offices. The opposition parties campaigned aggressively against demonetisation, saying it was bad for the economy and an inconvenience for the people and hoped it would create a backlash against BJP.

However, actually, as the election results show, demonetisation got a ringing endorsement. That this was on the cards in UP was evident in civic polls which took place a few weeks ago in Chandigarh and in states like Gujarat and Maharashtra and panchayat polls in Odisha state where BJP emerged as hands-down winner. In fact, Modi repeatedly hit back at opposition criticism of note ban by painting them black on the issue of black money. Even during the demonetisation drive, many Indians in both urban and rural areas were often heard saying that the intention behind the move was laudable but implementation left much to be desired. Clearly, the dynamics of politics in India has changed over the last two and a half years.