Mystique behind multi-phase polls
The 2014 general election, of course, remains seminal for it belonged to one man only - Narendra Modi - as the Hindu vote aggregated behind him in an unprecedented manner, cutting across all caste arithmetic. Then there are Bihar 2015 and West Bengal 2016 elections.
But before that, take a look at modern communication tools, which did not exist earlier, the widespread usage and prevalence of social media like WhatsApp, Facebook and YouTube in political electioneering. This is constant and continuous with political parties like the BJP mastering the art of feeding the electorate.
These tools play a big part in convincing people for they stay embedded in the subconscious threshold, enabling political formations to revise and reassess their strategies in each phase. In crunch situations before the voting in a particular phase, the type of messaging also plays a vital role, for it could be customized to that area's trials, tribulations or fears.
The party that maintains an initial lead as per people's perception attracts all such non-committed voters or vice-versa. Midway, something fresh emerges which can change the way people are voting. The 2012 UP joust saw fierce campaigning by Rahul Gandhi, but he just got squeezed in the war between the Samajwadi Party and Mayawati's BSP. Anti-incumbency against 'Behenji' and multiple voting phases saw the SP coming to power.
Look at the recent history of multi-phased polls: Lok Sabha poll 2014 (nine phases): BJP 281/543; Lok Sabha poll 2009 (five phases): INC 206/262; Lok Sabha poll 2004 (four phases): BJP 138, INC 145; West Bengal 2016 (seven phases): 211/294 seats to Mamata Banerjee; West Bengal 2011 (six phases) 227/294 seats to Banerjee-Congress alliance; UP 2012 (seven phases) SP 224/403; UP 2007 (seven phases): BSP 206/403; UP 2002 (three phases) SP 143, BSP 98, BJP 88, INC 25; and Bihar 2010 (six phases): 206/243 seats for NDA
In the 2017 UP state assembly polls, this same axiom paid in spades, the BJP won a landslide -- 324 out of 403 seats. It was held from February 11 to March 8, 2017 in seven phases. This election saw voter turnout of 61.04% compared to 59.40% in the previous election.