Viswanathan was returned to the State Assembly with a huge margin of votes when fresh elections were held in 1959 after the exit of the Communist Ministry headed by E.M.S.
He lent his powerful support and guidance first to the Coalition Government and later to the Congress Ministry in bringing about various land reform measures in the State.
Vishwanathan edited a Malayalam Weekly named The Republic and ably projected Congress policies and programmes which gained acceptance and support from the common people.
Besides, he played a prominent role in the adult franchise movement as a pre-condition to the induction of Responsible Government in the Cochin State.
During his tenure in the Congress, Viswanathan took a very keen interest in reorganizing the KPCC and secured far better representation on it for the Harijans, minority communities and the youth which enhanced the party's involvement in the lives of all categories of people in the State, lending it a greater democratic touch.
During his long and eventful public life in Kerala, Viswanathan could see through many an ambitious and progressive reform in political as well as social spheres.
Even amongst opposition party members there was great appreciation of his transparent sincerity and he was held in high esteem and affection for his qualities of head and heart.