Among all regional leaders of the country, it is M Karunanidhi who had the most powerful presence with his DMK ministers working in the cabinets of five prime ministers. Even though he headed a party which was once accused of harbouring secessionist tendencies, Karunanidhi has been the quintessential federal politician, who fought more Lok Sabha elections in alliance with national and regional parties than on his own. He has worked longest with the Congress party and paradoxically the grand old party is now a shadow of its old self, when it was ousted from power by the DMK in 1967.
Karunanidhi has held the DMK in his iron grip despite three upheavals -- first the major revolt by M G Ramachandran, which kept the DMK out out of power for 12 long years followed by minor revolts by charismatic Vaiko (in 1994) and recently by elder son M K Azhagiri.
Like his mentor and predecessor C N Annadurai, Karunanidhi knew that partnership with the party in power in Delhi was critical for a regional party. Being from Tanjore region, he wanted Tamil Nadu to have clout in Delhi for dealing the upper-riparian Cauvery state of Karnataka. Thus in 1971, Karunanidhi offered an alliance to Indira Gandhi, who had split the Congress party, against the grand alliance led by K Kamaraj and C Rajagopalachari. Karunanidhi offered just 9 seats to Congress (I), while CPI got 4 seats, but the alliance swept to power on Indira wave, with the DMK getting 23 seats in the Lok Sabha.
Even though the party had two seats less than what it had in the previous Lok Sabha, it was now a major supporter of Indira. But the split in the DMK meant Indira went for the MGR faction, and DMK's fortunes in the Lok Sabha hit rock bottom both in the Assembly and the Lok Sabha during 1977-1989 period.
But the long years in opposition made Karunanidhi common cause with diverse political leaders ranging from Jayaprakash Narayan to Jyoti Basu to N T Rama Rao to V P Singh, as they were all opposed to Indira and her son Rajiv. Karunanidhi's fortunes swung after the death of M G Ramachandran as Jayalalithaa struggled to take control of the AIADMK.
In 1989 even though the DMK did not win a single seat, the DMK had a cabinet minister in the National Front government of V P Singh and Karunanidhi used his clout to get the Cauvery dispute referred to a tribunal. The minister Murasoli Maran managed to get good amount of funds released. Maran, with his strong command of English and deep interest in national politics, became a key player. It helped Maran was Karunanidhi's favourite nephew also. But Rajiv Gandhi's assassination made Tamil Nadu overwhelmingly for AIADMK-Congress combination in 1991, making Karunanidhi a prominent member of the anti-Congress coalition. His patience paid as the state Congress unit split, with the G K Moopanar faction opposing an alliance with Jayalalithaa, and forming the Tamil Manila Congress. Karunanidhi, who had no MP in the Lok Sabha, gave generously one extra seat to Moopanar than DMK for the 1996 Lok Sabha polls. The anti-Narasimha Rao and anti-Jayalalithaa sentiment made every candidate of the DMK-TMC combination win, and Karunanidhi was back in business.
Maran was a prominent figure in the non-Congress governments of H D Deve Gowda, I K Gujral and A B Vajpayee, and DMK had found its permanent perch. In 2004, the DMK made what seemed a hopeless switch by joining the Congress front and ditching the BJP. By a whisker Congress was ahead of the BJP, and the UPA was born. Murasoli Maran's death brought his son Dayanidhi, who was more a businessman than a politician, as the powerful interlocutor during the two terms of Manmohan Singh. Karunanidhi had come to trust his family members -- son Azhagiri was the Union Minister for Chemicals and Fertiliers, while daughter Kanimozhi was brought to the Rajya Sabha, and the family interests dominated. Another DMK minister, A Raja, got embroiled in the mega 2G scam . The DMK's sun had dimmed in Delhi's corridors of power.
Apart from the Cauvery dispute which he pursued vigorously, Karunanidhi had strong influence on the country's Sri Lanka policy, first forcing the hasty withdrawal of Indian Peace Keeping Force from Sri Lanka in 1990 and later forcing successive governments to adopt a hardcore pro-Tamil policy.