Why India vote is big gamble for BJP
To be sure, Mr Modi is loved and loathed in equal measure.
His supporters believe his muscular nationalism and a carefully built reputation as a ruthlessly efficient administrator running the economically prosperous state of Gujarat make him a person fit to rule India. His critics insist he is India's most polarising politician, who refuses to apologise for the religious rioting under his watch in Gujarat in 2002.
The BJP believes India has moved on and that under Mr Modi's leadership they have their best chance of winning an election at a time when anger and disappointment with the incumbent Congress party is at an all-time high. Opinion polls appear to validate such optimism, giving the Mr Modi-led BJP a handsome lead over a subdued Congress.
Despite misgivings within a section of the party, the BJP has allowed a form of personality cult to grow around the controversial and charismatic Modi, critics say. He is anywhere and everywhere you look - in the newspapers, on the TV networks, on bus shelters, on the metro. He has run a fiercely energetic campaign, criss-crossing the length and breadth of India and speaking to packed public meetings. He is, as a friend says in jest, omnipresent.
Mr Modi represents a return to personalised politics, not seen in India since the days of Indira Gandhi in the 1970s. That was a time when she was controversially equated with India by an enthusiastic party elder and her Congress party used to win thumping majorities in what essentially was one-party rule.
Since the rise of regional parties and the fragmentation of Indian politics in the late 1980s, the country has been governed by multi-party coalitions. A total of 363 parties participated in the 2009 general elections, up from 35 in 1984. Most believe the maddening alphabet soup of regional parties points to healthier federalism. More significantly, the two main parties, the Congress and the BJP, won barely half of the popular vote in the last five elections.
Will that change this time round?
The BJP believes that Mr Modi's track record and charisma will lead to consolidation of votes in their favour and help the party to win an elusive majority. Others are not so sure. They believe the BJP's strategy to personalise the election is risky as voters not inclined to back Mr Modi, including Muslims who comprise 15% of India's voters, may unite to defeat him and his party.
Politics has become increasingly personalised in Western liberal democracies, partly because of the growth and reach of electronic media which feeds on personalities rather than issues. In India, Mr Modi has swamped the networks and saturated the air waves with his message in what many say is an attempt to portray himself as a presidential-style candidate.
But political scientists like Sanjay Kumar of the Centre for the Study of Developing Societies (CSDS), a leading Delhi-based think tank, sound a note of warning. Mr Kumar believes that the personalisation of politics is India is a "short-lived phenomenon", and will not last for very long in a "such a vast and heterogeneous country with strong regional parties".
If that's so - why has BJP put all its eggs in one basket?
Many say the party didn't have a choice, especially after losing two successive elections in 2004 and 2009 with ageing party patriarch Lal Krishna Advani at the helm. "They are trying an experiment with Mr Modi and are hoping to win," says Sanjay Kumar. "It may work or it may not."