India, May 30 -- BENGALURU Karnataka's political history offers a recurring warning for parties attempting to replace powerful regional leaders before the end of a term: the administrative transition may be immediate, but the electoral consequences often unfold slowly.

That history now hangs over Congress as Siddaramaiah exits the chief minister's office and DK Shivakumar prepares to take charge under a long discussed power sharing arrangement.

Inside the Congress, the transition is being viewed through the prism of two earlier political moments that altered Karnataka's electoral landscape far beyond the change of leadership itself. The first was the removal of Veerendra Patil in 1990. The second was B S Yediyurappa's resignation as chi...