It is important for OPS to ensure Madhusudanan's victory in the RK Nagar constituency that goes to polls on Thursday

In February, an inner voice reportedly spoke to O Panneerselvam at the J Jayalalithaa samadhi by the Marina in Chennai, resulting in a revolt and political upheaval in Tamil Nadu. On 21 December, when the inner voice of the voters of Jayalalithaa's constituency will speak to the OPS-led AIADMK through the EVMs, it could once again result in a political crisis.

In the past two weeks, OPS has done precious little apart from campaign for his party candidate E Madhusudanan. It is important for OPS to ensure Madhusudanan's victory in the RK Nagar constituency that goes to polls on Thursday. For this patch in north Chennai is not just any other constituency. It was represented by Jayalalithaa twice — in 2015 and in 2016 — and what the subtext of the victory, should it happen, will mean for the AIADMK is not lost on OPS. It will elevate the stature of the deputy chief minister and an orchestrated chorus celebrating him as the inheritor of Jayalalithaa's political legacy can be expected.

The past four months since the merger of the OPS faction with the Edappadi Palaniswamy camp, have been anything but smooth. There has been much discomfort within the erstwhile OPS group over denial of political goodies. Many senior leaders feel shortchanged by the coming-together as barring OPS, who got the party coordinator and deputy chief minister's post, no one else was politically elevated. They were made to sweat even to get the RK Nagar ticket for fellow camper Madhusudanan, who was Panneerselvam's candidate when the bypoll was to be conducted in April. A victory is sure to give the OPS camp muscle and lung power to throw its weight around within the AIADMK. And an assertive rival group within the ruling party won't please EPS too much.

But the chief minister knows a defeat would mean even more bad news. Should the AIADMK be unable to retain the seat and worse, lose to Sasikala's nephew TTV Dhinakaran or if the margin of votes between the two is insignificant, it will mean the two leaves symbol achieved zilch for the party. That could set the cat among the pigeons with many wondering if staying invested with EPS will fetch handsome returns in 2019 and 2021.

Then, there is the caste angle to the tug of war within the AIADMK as well. Ever since the ascension of EPS to the top job, the Gounder community has come to dominate the politics of Tamil Nadu. That is not music to the ears of the Thevar community that has held sway since the time Sasikala came into Jayalalithaa's life. Both Sasikala and OPS are Thevars, because of which the AIADMK was spoken of as a Thevar party.

Should Madhusudanan not put up a credible performance, Dhinakaran could act as the rival Thevar magnet for the fence-sitters from his community. The community realises that it needs a strong leader at the moment to take on EPS and his Gounder support system and the jury is out on whether OPS has the calibre to be that person.

The DMK's role in the RK Nagar election is a curious one. It has not run the kind of spirited campaign it was expected to, choosing local Maruthu Ganesh once again to contest the polls. Arithmetically speaking, it would be expected to win the contest, gaining both from the split in the traditional AIADMK vote between Madhusudanan and Dhinakaran, and retaining its core vote base. With 45,000 bogus voters removed from the electoral rolls, the DMK will fancy its chances.

But politically, MK Stalin will also be able to ring the death knell for the AIADMK with Plan B: Helping Dhinakaran win the contest and watching the fun unfold. A victory for Dhinakaran, despite being chargesheeted in the bribery case, with no party apparatus backing him and contesting on a new symbol, will enhance his stature. Unlike April, he is also campaigning using Sasikala's name and photograph — a sign of confidence that a lot has changed since the summer.

The BJP is not seen as a serious player in the contest, but is the punching bag for both DMK and Dhinakaran.

Both point out that a vote for Madhusudanan is a vote for the BJP that is hoping to cash in on the resentment against the national party for meddling in the internal affairs of the AIADMK. But given the demographic profile of RK Nagar and the emphasis on cash-for-votes, it is anyone's guess as to how much this will be a factor for the voters.

The by-election is the first electoral test after the demise of former chief minister Jayalalithaa and in a situation where elections to local bodies have been postponed more than once, the result on Christmas Eve although tainted by money power, will be seen as a barometer of the popular mood in Tamil Nadu.

Follow LIVE updates on RK Nagar bypoll here