The BJP's Chief Minister in Chhattisgarh, Raman Singh, is often called 'Mr. Clean,' mainly because of his transparent conduct and sincere work. That image of his is probably what gave the BJP the magic number to retain the central state. Raman Singh's welfare measures, particularly his rice distribution scheme, proved a hit with voters.
In contrast, the Congress is riddled with factionalism in the state. The PCC has admitted defeat, and says it will introspect.