Hyderabad, April 17 -- Parliament is preparing to vote on the Delimitation Bill, with a debate in full swing over whether it would tilt the balance of political power away from India's southern states. 

But what really is delimitation, and why are southern states fighting it?

Delimitation, in simple terms, is readjusting the borders of voting areas to ensure that each representative speaks for roughly the same number of people. As populations shift, grow, or shrink, constituency maps need to be updated so that political representation stays proportional. Demlimitation redraws the boundaries of Assembly constituencies to reflect the population numbers in Parliament.

The boundaries of India's Lok Sabha constituencies were last redra...