A new alliance takes over
What happened
Indian National Congress lost control to a coalition of several parties instead.
The Communist Party of India (Marxist) won the most seats in West Bengal, 80 of the 280, and governed as part of a wider alliance — a group of parties that team up to fight an election together, and share power afterward if they win enough seats between them.
That alliance, United Front II, held 190 seats in all, well clear of the 141 needed to govern.
The INC itself fell to 55 seats, a collapse from the government it had led.
What changed
The single biggest shift of the night ran in one direction, seat after seat.
41 seats moved from the INC straight to the CPM, more than any other party-to-party swing that year.
Across the whole assembly, 150 of the 280 seats changed hands from the previous election.
Notable numbers
A few numbers from that count stand out.
The tightest finish: Habibpur, West Bengal was decided by just 34 votes — the smallest margin, how far ahead the winner finished, in votes, over whoever came second, of any seat that year.
Raghunathpur, West Bengal had the widest winning margin of the year, at 55.2% of the vote.
Turnout — the share of registered voters who actually cast a ballot — reached as high as 81.3% in Sagar, West Bengal, a new high for the state.
The backdrop
This state's government changed hands twice in as many elections during these years, each time built from several parties rather than one.
The party now leading that new government had itself only recently become a fully separate, independently registered party.
On 7 November 1964, a faction of the Communist Party of India registered as a separate party, the Communist Party of India (Marxist), after a national leadership split within the CPI. From the 1967 West Bengal assembly election onward, CPI and CPI(M) contested as separate, independently registered parties in the state.