Here's your 10-point cheatsheet to this big story
Meghalaya was heading for a hung house when Conrad Sangma dialled the BJP's chief strategist Amit Shah for a renewal of their alliance. The state's ruling allies had decided to contest solo ahead of the election, following a rift over corruption allegations against the NPP.
Mr Sangma's National People's Party was the single largest party with 26 seats while the BJP won two in the 60-member assembly. The United Democratic Party, which was NPP's ally, emerged as the second-largest party, winning 11 seats – up from six in 2018. New entrant Trinamool Congress and the Congress won five seats each.
In Tripura, the BJP won 32 seats and its ally, the Indigenous People's Front of Tripura or IPFT, one, cruising past the half-way mark of 30 to retain power. The victory, though, was well short of the "tsunami" predicted by Chief Minister Manik Saha and below the BJP's 2018 score of 36.
The big headline was erstwhile royal Pradyot Manikya Debburma's Tipra Motha, which won 13 seats on its debut election and emerged as the second largest party in the state. The rise of tribal-backed Tipra Motha appeared to be at the cost of the BJP local partner IPFT, whose numbers slid from eight to one.
In Nagaland, the BJP retained 12 seats, its ally Nationalist Democratic Progressive Party or NDPP won 25 to gain a second term with a huge mandate. The alliance had won 30 seats in the last election. The state also had its first women MLAs since Independence, with the victory of both women candidates of the NDPP.
In his congratulatory message to the three states, Prime Minister Narendra Modi said the results show the people's "strong faith in democracy and democratic institutions in the country". "The way the northeast poll results have been extensively highlighted shows the region is neither distant from Dilli nor dil (heart)," the Prime Minister added.
This second mandate for the BJP in Tripura was a crushing defeat for the CPM, which ruled the state for 35 years. Ahead of the election, the party had tied up with Congress in what was seen as a last-ditch attempt to shore up its numbers.
But the Congress could only add three seats to their tally of 14. In Meghalaya, the Congress won just five of the 60 seats it contested and failed to open its account in Nagaland, where it fielded candidates in 23 of 60 seats.
New Congress chief Mallikarjun Kharge brushed off the party's electoral performance in the northeast, saying they were "small states" that go with "Central government trend".
It invited a swift rebuttal from PM Modi, who said the comment "is an insult to the mandate and the people of the northeast states". "Today's results have exposed Congress's thinking about the northeast," he said.
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