அனைத்து நெறிகளிலும்,வழிகளிலும் அண்ணா என்ற அற்புத நிலையை “அண்ணாவின் இதயக்கனி” புரட்சித் தலைவர் உருவாக்கினார்.
In 1972, DMK leader Karunanithi started to project his first son in a big way in film industry and also in politics. Understanding the tactics played by Karunanithi to corner him, MGR started to claim that corruption had grown within the party after the demise of Annadurai and in a public meeting asked for the financial details of the party to be publicised which enraged the leadership of DMK. Consequently, as expected, MGR was expelled from the party, and floated a new party named Anna Dravida Munnetra Kazhagam (ADMK), later renamed All India Anna Dravida Munnetra Kazhagam (AIADMK), the only powerful opponent of the DMK.He mobilized the period between 1972-1977 to spread and preach his party ambition with films like Netru Indru Naalai(1974), Idhayakani(1975) etc..,.
He became Chief Minister of Tamil Nadu on the 30th of July 1977, remaining in office till his death in 1987. The AIADMK won every state assembly election as long as MGR was alive. Although Anna Durai as well as Karunanidhi had acted in stage plays in trivial roles, in their younger days, before becoming chief minister, MGR was the first popular film actor to be a Chief Minister in India.Though the Congress won by a small margin of votes with the DMK in the 1980 parliamentary elections, the AIADMK under MGR won the state elections the same year. This made the Congress to ally with the AIADMK in the 1984 elections.
Once he became Chief Minister of Tamil Nadu, he placed great emphasis on social development, especially education. One of his most successful policies was the introduction of the "Mid-day Meal Scheme" introduced by the popular Congress Chief Minister and Kingmaker K Kamaraj to a nutritious Mid-day Meal Scheme in the Government-run and aided schools in Tamil Nadu. He also introduced Women's Special buses.
He introduced Liquor ban in the state and Preservation of old temples and historical monuments, ultimately increasing the state's tourist income. He set up a free school for the Cinema Technicians children in Kodambakkam called MGR Primary & Higher Secondary School which provided Free Mid-Day meals in the 1950s. He led the ADMK to victory in the 1984 assembly elections despite not taking part in the campaigning. At that time he was undergoing medical treatment in America and his images were broadcast in Tamil Nadu through cinema halls. This was an effective campaign and ADMK won the elections, indicating the depth of his popular support.
He won the election in a double landslide victory in 1984.He still holds the record of being the chief minister with the highest consistent longevity of more than a decade.MGR in every way of his rule followed Arignar Anna and established that he was the Heart Fruit [Idhayakkani] of Arignar Anna.