Only two chief ministers have had relatively long tenures. The Congress grandee K Kamaraj ruled for nine years from 1954 to '63, and the matinee idol MG Ramachandran of the AIADMK - MGR to fans - for a record 10 years from 1977 until his death in December '87.
Since then, the voters have been choosing between DMK's M Karunanidhi and AIADMK's J Jayalalithaa. Going by this trend, Jayalalithaa should now give way to Karunanidhi.
Only, this election, the top job may go to Karunanidhi's son and heir-apparent MK Stalin.
Although twice acquitted after being convicted by a lower court for corruption, Jayalalithaa's political future still hangs in the balance as the Supreme Court is hearing the Karnataka government's appeal against her acquittal in a Rs 56-crore disproportionate assets case. However, the chances of the court deciding the appeal anytime soon, specifically before the state votes on 16 May, are remote.
If Jayalalithaa is in her 60s and not exactly in the pink of health, Karunanidhi is 92 and wheelchair-bound though mentally agile. The burden of running the campaign has fallen to Stalin, who is unofficially being projected as the chief ministerial candidate.
AIADMK's fortunes will hinge on Jaya's ability to campaign. But will her delicate health permit her?
There is an anti-incumbency wave against the Jayalalithaa regime, seen as corrupt, inefficient and non-performing. But the alternative DMK-Congress alliance is no better as the UPA II, in which they were partners, was marked by the 2G scam, in which Karunanidhi's daughter Kanimozhi is an accused, as well as the coal and Commonwealth Games scams among other scandals.
Moreover, the previous DMK government was one of the worst Tamil Nadu has seen in recent years, marked as it was by corruption and family rule. Not surprisingly, the party was pushed to third position in the 2011 election which returned Jayalalithaa to power. Vijayakanth, whose DMMK stood second, became the Leader of the Opposition.
No strong force
But when the actor-turned-politician refused to play a friendly opposition leader, Jayalalithaa clipped his wings by luring away nine of his MLAs. And when on the eve of this election he declared that he would rather be king than kingmaker, the rebel MLAs promptly resigned their seats and the Speaker announced that Vijayakanth was no longer the Leader of the Opposition.
Having projected his party as an alternative to the DMK and the AIADMK, Vijayakanth had to go it alone. So, when Karunanidhi tried to persuade him into an alliance, likely with the intention of neutralising him later, he got a snub, "No, thank you."
The BJP has been in the reckoning in Tamil Nadu only in the 1998 and '99 Lok Sabha polls thanks to its alliance with, respectively, the AIADMK and the DMK. It hasn't built on that success. As a result, its former NDA partners such as the MDMK and the PMK have deserted it. No surprise Vijayakanth also cold-shouldered the party when it approached him.
After prevaricating, Vijayakanth has decided he would rather be the "captain" of his own team than of a wannabe third front of Vaiko's MDMK, the two left parties and the Dalit outfit Viduthalai Chiruthaigal even though they were willing to let him lead the alliance - called Makkal Nala Kootani or the People's Welfare Front - as the chief ministerial candidate.
The hype around Vijayakanth is based on the assumption that his one-time high vote share of 10% is still intact. He party debuted in the 2006 assembly election and polled 8.5% of the vote, but he was the only candidate to win. In the 2009 Lok Sabha election, he increased his vote share to 10.5% but how much of it was his own is not known as he contested as part of the NDA. If this wasn't enough to doubt his chances, his haughty behaviour over the last five years doesn't inspire confidence.
Stalin is the favourite to be the next Tamil Nadu CM. But he'll have to watch out for his brother
As for the "third front", none of its leaders has been in power and thus lack administrative experience. All have been part of either the AIADMK or the DMK in the past.
Anbumani Ramadoss of the PMK, on the other hand, has been the Union health minister and is a suave campaigner. But his appeal, and that of his father S Ramadoss, is confined to the Vanniar-dominated northern Tamil Nadu.
In driver's seat
The DMK has just finished the first round of seat-sharing talks with the Congress. Senior Congress operatives Ghulam Nabi Azad and Veerappa Moily met Karunanidhi in Chennai on Friday in this regard.
A day before that, Stalin's estranged elder brother MK Alagiri called on Karunanidhi, much to his chagrin. Alagiri has not only refused to accept Stalin as his leader as long as Karunanidhi is around, he has also condemned the alliance with the Congress as shameless and opportunistic. Karunanidhi reportedly wanted to patch up with Alagiri as he has a strong base in Madurai and other southern districts, where Vijayakanth is also perceived to be strong.
Jayalalithaa, in a belated clean-up, has axed several tainted ministers, while OP Pannerseelvam, who twice filled in as chief minister when she was forced to step down following a court verdict in the part, has been rehabilitated after having put in the dog house.
Since Jaya's is a one-woman army, her party's fortunes will hinge on her ability to campaign. Will she be able to weather the heat and dust of the campaign trail given her delicate health?
The people of Tamil Nadu have always voted decisively. The only exception was in 2006, when they chose the DMK-Congress combine instead of giving a clear majority to the DMK. It's another matter that Karunanidhi refused to share power with the Congress and ran a minority government even while enjoying a berth in the UPA ministry.
Faced again with Hobson's choice, the voters may plumb for Stalin as he is of the same age as Jayalalithaa, is untainted by corruption and has a proven record of performance as two-time mayor of Chennai and local ministration minister in the last Karunanidhi government.
This is Stalin's chance to prove his mettle. Is he up to the task?