One fallout of conducting the Lok Sabha polls in seven phases is that political parties, through their own commissioned exit polls, start getting an idea of how they are performing.Accordingly, they recalibrate their campaign messaging in different phases, as BJP has been doing – from Pulwama to Pragya Thakur.The media also conducts its own exit polls and adjusts its political commentary. All this seeps into the larger political grapevine – after the first few phases, a prominent news TV anchor suggested that the real election might begin after May 23.Also read: You Had One Job, Rahul GandhiNo wonder there is a growing murmur after the first four phases of polling – possibly based on exit poll trends – that the BJP is not doing as well as expected even though it is expected to remain the single largest party. The opposition, the mahagathbandhan, is doing reasonably well in Uttar Pradesh where the BJP’s losses could be significant. This was further reinforced by Bahujan Samaj Party supremo Mayawati and Samajwadi Party leader Mulayam Singh sharing a stage and sending a clear message of vote transfer among their voters.The BJP is worried about this.If BJP loses about 40 of the 80 seats in UP, as against the 71 seats it bagged in 2014 amidst a Modi wave, there is a real possibility that its overall tally gets confined to 180-190 and the NDA fails to cross the 220-225 mark.This could happen realistically if the Congress manages to win an additional 40 to 50 seats in Hindi-speaking states as well as Gujarat, where it has largely been a one-on-one fight with the BJP.So what happens if the NDA is confined to around 220 seats? In that event, Modi will try to woo the southern states where K. Chandrashekhar Rao of TRS, YRS Congress’ Y.S. Jaganmohan Reddy or Naveen Patnaik of the Biju Janata Dal could be new potential allies for the BJP. Modi may even try to win over the DMK, which is presently a part of the UPA.“Our immediate objective is to stop Modi from forming a government. All regional parties are agreed on this,” Mamata Banerjee told reporters in Kolkata recently.It is unlikely that Mamata Banerjee, Akhilesh Yadav or Mayawati will show any inclination to join the NDA in the initial round of political negotiations.It is more likely that the BJP will woo southern parties first as BJP wants to make its presence felt in the south. These potential allies will then calculate whether it is better to go with the BJP or attempt a broader non-BJP coalition.After all, if the NDA gets confined to 220-225, the non-BJP coalition will have 315 -320 seats.It is very likely that regional leaders like KCR and Reddy – whom Modi is banking on – may think that they could leverage greater power by joining a larger coalition where no single party has a sway.Additionally, regional leaders are quite wary of the creative and selective way in which the Modi government has used investigation agencies against them quite ruthlessly.Post-poll arithmeticSo if most regional leaders opt for a non-BJP coalition, then it is possible that a non-controversial, low-key leader from the south will be chosen to lead a coalition which may or may not be led by the Congress.The Congress, if it gets over 100 seats, could project one of its southern leaders as the head of a coalition with a more diffused sharing of power. In the past, it has been seen that in the event of a fractured verdict, a southern leader emerges as a consensus candidate because there are too many claimants in the north which makes it difficult to choose a PM candidate. Narasimha Rao and Deve Gowda are two examples of low-key candidates who led governments when no single party got a full majority.Also read: Debate: Some Coalitions Are StupidIndeed, if a similar situation arises again, Rahul Gandhi could well propose a southern Congress leader as a possible candidate to head a coalition. The Congress has laid special emphasis on expanding its influence in the south with Rahul Gandhi picking Wayanad as a second Lok Sabha seat. So it makes logical sense for Rahul to choose a PM candidate from the south to head a coalition. The southern CMs had formed a lobby group a while ago to demand equity in the federal fiscal transfers. So the time may be ripe for them to send a southern PM candidate, belonging to any non-NDA party.Besides, as Mamata Banerjee told a few travelling journalists after a public meeting at Rajarhat, “Our immediate objective is to stop Modi from forming a government. All regional parties are agreed on this.”Upon being asked what happens if the NDA is short of a majority by just 30 to 40 seats, Mamata confidently shot back: “We will still ensure Modi is out.”Mamata also hinted that all regional leaders are in touch with each other and they are all seemingly ready to execute a “Karnataka” on BJP after the results are announced on May 23.