New Delhi, April 22 -- On Thursday, Tamil Nadu and West Bengal-two states with sharply different political rhythms-head to the polls. Tamil Nadu will vote in a single phase across all 234 seats, while West Bengal begins its first phase in 152 of 294 constituencies.

Both contests will test the Bharatiya Janata Party's (BJP) momentum: it has little presence in Tamil Nadu but poses a serious challenge to the Trinamool Congress (TMC) in West Bengal.

Mint explores:

West Bengal has a history of extended single-party/alliance rule. The state was governed by the Left Front, led by the Communist Party of India (Marxist), for 34 years before Mamata Banerjee's rise ended that run in 2011. The pattern has largely endured since. The Banerjee-led TM...