The Tamil Nadu election did not throw a surprising result, as the Dravida Munnetra Kazhagam was largely expected to win against the beleaguered and divided All India Dravida Munnetra Kazhagam . The DMK commanded over a larger alliance of parties, had a comparatively smoother transition of power after the death in 2018 of its historical leader, M Karunanidhi, and led a disciplined campaign that mixed regional and national themes.

After a decade of AIADMK rule and the turmoil that party has been since the death in 2016 of its leader J Jayalalitha, a swing in favour of the DMK and its allies seemed highly likely.

But considering the adverse political context, AIADMK did not do that badly, for a party in disarray. It lost 7% of vote share compared to 2016, which is a small swing in Tamil Nadu Elections. On the other hand, the DMK gained 6% of vote share. There is only 4% of vote share difference between the two parties but that difference produced very different results in terms of seats: the DMK won 70.7% of its races, against 34.5% for the AIADMK. As a consequence, the DMK won twice the number of seats than to its opponent.

An examination of the data of this election shows that this was not the one-sided contest that Tamil Nadu often produces, with its big swing elections. The DMK alliance has secured an absolute majority with over two-thirds of the seats. With 133 seats, the DMK commands a single majority of seats on its own. Its partners bring 26 additional seats.

But the AIADMK stayed resilient with 66 seats. Its partners, the BJP and the Paattali Makkal Katchi, added nine seats to the alliance’s tally. This is a much better performance than the 2019 election, where the AIADMK and its partner, the BJP, were swept away. The DMK and its partners (including the Congress and the Left) bagged 96% of all 234 assembly segments, in a referendum election against the BJP.

Even though national and state elections differ, there were similarities between the DMK campaign themes. In 2019, it held its campaign on the back of the NEET medical entrance exam controversy, the ban on the bull-wrestling pastime of jallikattu, the farmer’s protests in Tamil Nadu and the shooting of protestors at the Sterlite plant. It campaigned on matters of regional identity, attacked the BJP’s impositions and made the AIADMK look bad on all these issues by association.

In 2021, the DMK also mobilised on the theme of protecting Tamil Nadu’s regional identity against majoritarian forces from North India, associating the BJP’s local partner, the AIADMK, to those threats.

Even though the BJP still does not have a strong presence in the state, it won four seats of the 20 it contested with slim margins, and by virtue of its alliance with the AIADMK. One has to go back to 2001 to see the BJP win seats in the state. At the time, it was in partnership with the DMK.

Other alliances of small parties did not fare well in this election. The alliance led by Amma Makkal Munnettra Kazagam secured only 2.8% of vote share while the alliance led by actor Kamal Haasan’s Makkal Needhi Maiam party got only a 2.7% vote share. They failed to win any seats.

The fact that both the DMK and AIADMK broadened their alliances to include many small or local parties did not leave space to others to perform.

One notable exception is the Naam Tamilar Katchi, (“We Tamils Party”), led by the film-maker and Tamil Nationalist ideologue Senthamizhan Seeman, which contested on its own and won 6.6% of vote share, against 1.1% in 2016. In 2019, it secured a 3.9% vote share.

Eroding participation

Participation in Tamil elections has been declining over the past two elections. In 2011, 78% of voters cast their ballots. That number went down to 75% five years later and to 73% in 2021. It is hard to say why this is happening, when participation is increasing across most states in India.

Perhaps the extensive urbanisation is a cause for such a turnout. It is worth noting that Tamil Nadu is 48% urbanised as compared to national average of 30%.

The is a uniform dip in voter turnout across regions and some variations between them. Turnout is lowest in the northern region, which includes Chennai. Lower voter turnouts in the south and the northern regions could be due to migration.

Gender-wise, the gap between male and female voters in Tamil Nadu closed in 2011. That gap used to be quite wide in the 1970s and had already reduced by 1984.

The gap between male and female voter turnout is almost overlapping with one another. This means that women play an important role in shaping results in Tamil Nadu. The small gap in participation between men and women may account partly for the many pro-women legislations and schemes enacted by successive governments. There is an element of electoral compulsion to cater to the needs of a large women electorate.

A growing pool of parties and candidates

The dominance of Tamil Nadu’s party system by the two Dravidian parties does not deter citizens from contesting elections on their own, either as independent candidates or as members of small, local parties.

The 2021 saw 4,232 individuals contesting, a number that has consistently increased since 2001 (after 1996, the deposit to contest an election was raised by the Election Commission, to trim down the number of candidates). That is a robust 18 candidates per seat, on average. Of these candidates, 3,520 lost their deposits (obtaining less than one-sixth of the votes polled in the seat in which they contested).

Similarly, a record 109 parties contested the 2021 election, again a sharp rise compared to previous years. Only eight of them found their way to the Vidhan Sabha. This is four more than in 2016, when the DMK, AIADMK, the Congress and one MLA from the Indian Union Muslim League – Muhammed Abubacker, in Kadayanallur – obtained representation.

The gap between the number of contestants and the reduced diversity of parties in the assembly is an illustration of the continued dominance of the DMK and AIADMK, both electoral pivots around which small parties need to ally to hope to convert their votes into seats.

Geography of the results

The map of the 2021 results shows that party performance tends to be clustered in specific areas. Each party possess a number of strongholds that they keep over time. The DMK has increased its seat share across the geography of the state but to a lower degree in the west and south compared to the north and central regions.

The western and southern regions are regarded as favourable to the AIADMK. In 2021, the DMK made significant inroads in the south.

The 2021 map also shows that small parties and Dravidian parties’ allies have a very localised presence. The Viduthalai Chiruthaigal Katchi won its seats in coastal areas, in Kanchipuram, Cuddalore and Nagapattinam districts (In 2019, it had won the Chidambaram seat).

The Paattali Makkal Katchi is present in the northern and western region, across the Dharampuri and Salem districts. It also won the Mailam seat in the Northern Region. The left won three seats near Thiruvarur and one seat in Thalli, next to the Paattali Makkal Katchi seat.

The BJP won the seats of Coimbatore South and Modakuruchi in the western region, Tirunelveli and Nagercoil in the south.

Congress seats are literally scattered in the four corners of the state. Barring one seat in the western region – Udhagamandalam – and the seat of Erode, it is completely absent from the state’s hinterland. In the 2019 election, the Congress won an impressive 51 assembly segments, a performance it is not able to transpose to state elections, where its partner, the DMK, restricted the number of seats it gets to contest, owing to its performance in 2016 polls (8/41).

In 2016, the DMK resisted well the AIADMK wave in the northern region and in the Dindigul district. Otherwise, the AIADMK swept the state.

A not-so closely fought election

Party-wise victory margins show us that barring two strong performances from the Communist Party of India, most parties won their seats with relatively close margins.

The DMK’s median victory margin is at nearly 12%, which indicates comfortable wins. The AIADMK’s median victory margin is lower, at 8%, which tells us that it had to fight more to win seats. The BJP and the Viduthalai Chiruthaigal Katchi won their seats with very thin margins.

But overall, most seats were won with margins above 10,000 votes. In only 39 seats was the victory margin inferior to 5,000 votes. The DMK won 17 of those seats, the AIADMK 12, the Congress four and the BJP, Viduthalai Chiruthaigal Katchi and Paattali Makkal Katchi won each two of those closely fought seats.

This shows that small vote variations could have led the DMK to perform significantly less than it did, and that small numbers can still make big differences in Indian elections.

The map shows that high and low margin victories are not concentrated in any particular regions. In Kanchipuram, the DMK candidate Sundar K won by 91 votes. In Athoor, DMK’s candidate Periyasamy I won by 135,571 votes, a 59% margin.

Dravidian parties domination continues

The next three graphs show us the sustained dominance of the DMK and the AIADMK across five decades. The see-saw performance of both parties, characteristic of the 1980s and 1990s, led to a period of greater dominance of the AIADMK, under Jayalithaa, who would serve five times as chief minister between 1996 and 2016.

The mid-1990s and the early 2000s were a period of decline for the DMK, which has seen a revival since the 2016 election. This is the first time that it crosses the AIADMK in vote share since 2001.

This chart also shows the continuous decline of vote share of the Congress and of small parties, like the DMDK. That being said, if the DMK and AIADMK dominate the political stage of Tamil Nadu, they do not occupy the entire space.

Small, local parties and independent candidates regularly gather between 20% to 25% of the votes in Tamil Nadu elections. This means than roughly one voter out of four is unconvinced by the two major offers on display.

Between 1996 and 2006, that figure went up to 30%-35%. This means that the AIADMK’s dominance in that period was also sustained by a fragmentation of the votes around it, which enable it to command larger majorities even with fluctuating vote shares.

These aggregate vote share comparisons have limited value, however, since both parties contest with partners and therefore don’t run in every seat.

Comparing the performance of the DMK and the AIADMK in the seat where they contest shows that since 2001, the two parties are actually closer to one another in terms of vote share performance.

The see-saw effect is much more visible when we look at seat share. Small vote variations, in a first past the post electoral system, create what political scientists call a disproportionality effect. It is the distribution of votes around the main party that determines the conversion of votes into seats. Thus, the massive swings we see in Tamil politics are also generated mechanically, by the combination of a fragmented political landscape and the electoral system.

In India, majorities are always the product of fragmentation, not unity.

This mechanics of elections of course also contributes to the centrality of both Dravidian parties. The success of smaller or other parties than DMK and AIADMK depends on their alliance with either of the parties, as a result of which the votes of the small parties get converted to seats through their alliance with Dravidian parties. This is the only way a party like the BJP can get seats in Tamil Nadu, also.

In recent elections, however, the presence of small parties in the assembly has been greatly reduced. This comes from the fact that both Dravidian parties are not willing to give away many seats to their partners, keeping the lion’s share.

In this election, the AIADMK gave 20 seats to the BJP and 23 seats to the Paattali Makkal Katchi. Given their performance, it was quite a few seats too many. On the other side, the DMK gave 25 seats to the Congress (who won 18 of them), six seats to the Viduthalai Chiruthaigal Katchi, three seats to the Indian Union Muslim League, and six seats each to the Communist Party of India and the Communist Party of India (Marxist).

AIADMK got dragged down by its partners

Strike rates are a good way to compare the performance of parties within their alliances.

The overall figures show that the DMK and its partners converted 68% of the 234 seats they contested into victories, against 32% for the AIADMK alliance.

At the outset, the DMK alliance was much broader than its opponent’s. One hundred and eighty seven candidates contested on the DMK’s Rising Sun symbol. Fourteen of these candidates actually came from other small parties but contested under the DMK banner: Marumalarchi Dravida Munnetra Kazhagam (6), Aathi Thamizhar Peravai (1), Makkal Viduthalai Katchi (1), Kongunadu Makkal Desiya Katchi (3), Manithaneya Makkal Katchi (2), Tamizhaga Vazhvurimai Katchi (1) and All India Forward Bloc (1).

The DMK won 125 of the 173 seats its candidates contested. The other small allies won eight of their 14 races (Marumalarchi Dravida Munnetra Kazhagam, 4; Kongunadu Makkal Desiya Katchi, 1; Manithaneya Makkal Katchi, 2; Tamizhaga Vazhvurimai Katchi, 1).

The DMK and associates’ strike rate stands at 70% (72% for the DMK minus the 14 candidates from other parties). The Congress has an even higher strike rate of 72%. The Viduthalai Chiruthaigal Katchi follows at 67%. The communists, who contested only 12 seats, got a 33.3% strike rate.

The AIADMK alliance on the other hands sees great variation in performance between the three partners. The BJP and the Paattali Makkal Katchi trail their senior partner at 20% strike rate. This shows that the AIADMK’s partners dragged it down, and that vote transfers between parties were more effective on the DMK side.

This means that the BJP was a liability to the AIADMK in this election. Its slip-ups included Adityanath’s disastrous speeches in Hindi and the violence surrounding his visit in Coimbatore last March. Besides, with Tejaswi Surya’s bizarre tweets about the need to de-Periyarise Tamil Nadu, the AIADMK did not do itself a favours by embarking the BJP in its boat.

Since 2017, there has been a revival of anti-Hindi imposition protests in Tamil Nadu, which also put the AIADMK in an awkward position.

Sub-regional analysis

We already saw that there is a geography to electoral victories in Tamil Nadu. Breaking the data by sub-regions is another way to observe these variations.

The DMK won in three of the four sub-regions: the central, northern and southern regions. The AIADMK was ahead, by nearly 6% vote share, only in the western region. It obtained its lowest vote share in the southern region, one of its traditional strongholds.

These variations are greatly amplified when we look at the conversion of votes into seats. The DMK strike rate in the central region is at a whopping 81%, against 55% in the northern region (its traditional stronghold) and 31% in the southern region.

These goes to show that the notion of party stronghold is not carved in sandstone and that there is still a lot of fluctuation in party performance, across regions. The 2011 election’s map shows for instance that the AIADMK swept before in areas that the DMK dominated in subsequent elections.

There are also political aspects to these variations. In the south, the AIADMK lost ground due to an effective campaign by the DMK and the Congress. But it also suffered split voting from AMMK candidates.

Party-wise strike rate by regions show that all DMK partners, alongside the DMK, performed extremely well. Of course, they owe this performance to their alliance with the DMK. But still, these high strike rates are clear signs of rejection of the AIADMK government and alliance.


The Tamil Nadu assembly has 44 seats reserved for members of the Scheduled Castes and only two seats reserved for the Scheduled Tribes. The DMK alliance won 28 Scheduled Caste seats (21 with DMK candidates) against 16 by the AIADMK. All in all, there is no major difference of performance between the two parties in reserved seats, compared to general ones.

In 2021, the DMK had given a significant number of the Scheduled Caste seats to alliance partners, a few of which are local Dalit parties, such as the Aathi Tamizhar Peravai.


This data tells us that the DMK won a clean victory but that the AIADMK remained a competitive adversary. The DMK returns to power after ten long years, putting an end to a longer period of decline. This augurs well for its new leader, MK Stalin, who leads a party with strong organisational capacity.

This article is not the place to interpret the reasons that led to this victory. But we note that in 2019 and 2021, the election was won by a party that succeeded in incarnating a strong regional identity and form a large alliance not simply against a local adversary but against Hindu majoritarianism.

The DMK campaigned on the theme of regional identity, expressed in terms of cultural and even civilisational integrity. It campaigned as much against the BJP, which does not really have a presence in the state, than the AIADMK. Attacking the BJP on general interest issues was also a good way to make the AIADMK look bad by association.

But the fact that the AIADMK alliance has managed to recover its vote share from one-sided 2019 polls signals that the party’s organisation remain strong. It prevented the DMK to get the “crushing victory” it aspired to and shows that power equation in Tamil Nadu remain balanced.

Gilles Verniers is Assistant Professor of Political Science at Ashoka University, co-Director of TCPD and Visiting Senior Fellow at the Centre for Policy Research.

Vignesh Karthik KR is a doctoral researcher at the King’s India Institute, King’s College London.

Mohit Kumar and Neelesh Agrawal are Research Engineers at TCPD.