Why are regional parties prone to a split?

After defeat in West Bengal polls, TMC is facing a split. India has seen such disintegrations earlier too. But, why do regional parties face the split?

Equating Nazi Germany and India: Comparing apples with oranges

Bengal’s new government acts on long-ignored border fencing

With the new BJP-led government now moving ahead with land handover for fencing, an old border deadlock has suddenly re-entered the spotlight. But why did this issue remain unresolved for so long? Was BSF repeatedly pushed to the sidelines as political considerations and vote-bank calculations shaped key decisions by the previous government?