The formation of a grand alliance of the Congress, All India United Democratic Front (AIUDF), three left parties, and a newly floated regional party will influence the poll arithmetic in the assembly polls in Assam. The electoral politics is a game of numbers and the combined votes of these parties will be significant number which the ruling coalition can least afford to ignore. The vote shares of the constituents of the grand alliance in 2016 assembly polls explain this political reality for the BJP. The Congress vote share was 32.06 per cent in the 122 seats contested by the party. The AIUDF vote share in 74 seats contested by the party was 21.34 per cent. The CPI(M) polled 3.38 per cent votes in 19 seats contested while the CPI polled 2.10 per cent votes in 15 seats contested by the party. The CPI(ML) vote share in seven seats contested by the party was 2.01 per cent. The Congress, AIUDF and the Left parties did not have alliance in last Assembly polls. However, alliance politics is not so simple as transfer of votes in favour of the common candidate often do not happen if the party loyalists are opposed to decisions of the leaders in respect of seat sharing. Disgruntled ticket aspirants turn out as the biggest spoilers by contesting as rebel candidate against the common candidate of pre-poll alliance. How far the grand alliance succeeds in overcoming all such hurdles will only be seen once the constituent parties finalize the seat-sharing deals. This holds equally true for both ruling and opposition camps. The BJP has succeeded to some extent in creating confusion, particularly among a section of Congress leaders and workers against this alliance by projecting the Congress-AIUDF alliance as an unholy alliance and detrimental to the interest of indigenous people. The BJP has been harping on the fact that the AIUDF was formed after the Supreme Court scrapped the erstwhile Illegal Migrants (Determination by Tribunals) Act, 1983 which posed a stumbling block in detection of illegal Bangladeshi migrants. The ruling party is counting on sentiment against an electoral with the AIUDF as a constituent among indigenous voters to retain its influence in indigenous communities dominated seats in the Brahmaputra valley. Of the 60 seats won by the BJP in 2016, 49 came from the Brahmaputra valley when the Congress, AIUDF and the Left parties contested separately. The BJP cannot ignore this political reality as the scope to increase its tally in the Brahmaputra valley will be limited given the new political equations. Besides, the BPF was a major constituent of the ruling alliance in 2016 which added 12 seats to the coalition. The formation of the new regional parties – Assam Jatiya Parishad (AJP) and the Raijor Dal have caused erosion in the AGP support bases. The combined vote share of BJP, Asom Gana Parishad (AGP) and the Bodoland People's Front (BPF) was 41.5 (BJP-29.5, AGP- 8.1 and BPF-3.9) per cent. Replacement of the BPF with the United People's Party, Liberal as the new constituent of the ruling alliance is not going to give the same edge as the results of the elections to the Bodoland Territorial Council have indicated. The BJP has exuded confidence that formation of the grand alliance or the alliance between the new regional parties will not have any impact on the poll outcome and prevent it from retaining power at Dispur. The ruling party has focused on achievement of the government led by it and activities of the party to strengthen the base. It can hope to derive benefit from this campaign as performance of the incumbent government is much better than previous regimes as far as ensuring last mile delivery of various welfare schemes are concerned. The ruling coalition has already projected incumbent Chief Minister Sarbananda Sonowal as the chef ministerial candidate for a consecutive term. Compared to this the grand alliance has not been able to project a chief ministerial candidate. Projecting a chief ministerial candidate by the AJP and Raijor Dal is also going to be difficult for the two new regional parties. This will give the BJP-led coalitionan edge over the alliances of opposition parties. The BJP is also exuding confidence in its organisational capacity of influencing voters at the polling booth level. The AJP has already formed 4,600 booth committees and announced plans to constitute over 27,000 polling booth-level committees which the BJP will find difficult to ignore. Two back-to-back public rallies of Prime Minister Narendra Modi and Union Home Minister Amit Shah scheduled for this weekend will set the tone of electioneering of the ruling coalition in the state. The formation of the grand alliance will pose a tougher challenge than perceived, and the BJP will have to pull out all out all stops to counter it.