When the incumbent Left Democratic Front (LDF) swept the Kerala Assembly polls in 2021, it defied the state’s four-decade-old pattern of power alternation, under which the Communist Party of India (Marxist)-led LDF and the Congress-led United Democratic Front (UDF) had flipped power in every election since 1982.The election saw an overwhelming majority of seats reelecting the incumbent alliance. 115 seats or over 82 % of Kerala's total 140 Assembly seats voted for the same alliance in the 2016 and 2021 polls. In other words, just 25 seats voted for a change from 2016 to 2021.Among those 115 seats, LDF reclaimed 83 seats, enabling it to halt Kerala's political pendulum of last eight elections. Whereas UDF could register win in just 32 of these seats – most of which were clustered in pockets of Malappuram, Palakkad, Ernakulam, and Kottayam.Going back further to 2011 state elections show 27 fewer seats that voted for the same alliance. A total of 88 seats or about 63 % of all seats elected the same alliance in the last three Assembly polls – 2011, 2016, and 2021.59 of these seats were loyal to LDF and 29 seats stuck with UDF.Now, we change the map as the delimitation in 2008 changed the borders and composition of state's Assembly constituencies.Here we look at the 26 constituencies that resisted Kerala's alternation pattern between 1982 to 2006. Sixteen of these seats were consecutively won by LDF and 10 were fortresses of UDF.LDF's Loyal Seats in Kerala (1982-2006)Trikkarpur / Thrikaripur: CPI(M) has been the undisputed winner from this seat ever since the constituency was carved out in the 1976 delimitation, replacing the previous Nileshwaram constituency. The only Assembly polls when Left could not win from here was the 1960 elections. This was a controversial election, conducted after Congress government at the Centre dismissed the democratically elected Left government in Kerala – which was the first non-Congress state government in the country. Incidentally, India's first non-Congress chief minister, EMS Namboodiripad, was the first winner from this seat in 1957, which was also Kerala's first Assembly election after the state's formation in 1956.Payyanur: CPI(M) has never lost this seat since its formation i.e. in 1967.Taliparamba: This seat has been a CPI bastion since its inception in 1967. The only instance when the Communists lost this Assembly seat was in 1970, when Congress' CP Govindan Nambiar defeated CPI's incumbent KPR Poduval with a margin of less than a thousand votes.Edakkad: LDF had an unwavering hold over this constituency, which is now defunct after the 2008 delimitation. The Left allies had won all the Assembly elections from this seat, except that in the 1970 polls when Congress had won from here.Thalassery / Tellicherry: LDF has had an absolute hold over this seat since Kerala's first Assembly polls in 1957.Kuthuparamba: Before the 2008 delimitation, this seat had voted for an LDF candidate, without a break, from 1970 to 2006. Leaders like Pinarayi Vijayan and KK Shailaja have been elected from this seat in the past.Vadakara / Badagara: This seat has been consistently returning the candidates LDF since 1977.Nadapuram: The constituency has had a stronghold of CPI since the first Kerala Assembly elections in 1957. The only state polls where CPI lost from Nadapuram was the 1960 elections when the Indian Union Muslim League (IUML) had won from here.Meppayur: Except for the 1970 and 1977 Assembly elections, when IUML had won from here, Meppayur has been LDF's stronghold. The constituency got defunct in the 2008 delimitation.Balussery / Balusseri: LDF parties have an unbreakable streak of win from this Assembly seat since 1982.Beypore: This constituency has been an LDF bastion since its formation in 1967. The lone election when the Left front lost from here was in 1977 Assembly polls.Malampuzha: It's a sure-shot seat of CPI(M). They have never lost an Assembly election from here. This has also been the seat from where former Kerala chief ministers EK Nayanar and VS Achuthanandan reached the state Assembly.Coyalmannam: The constituency existed from 1977 to 2006, during that period CPI(M) was undefeatable from here.Cherpu: During the existence of this constituency between 1977 to 2006, it has only elected candidates from CPI.Kilimanoor: Since this constituency was formed in 1965, till it was decommissioned in 2006, it elected an LDF representative. The 1965 and 1967 Assembly elections from this seat were won by CPI(M) and from 1970 onwards it had purely been a CPI seat.Vamanapuram: This seat has been a CPI(M) fortress since its inception in 1967. The only time when it lost Vamanapuram was in 1970, when Congress registered a marginal win with about 1800 votes. UDF's stronghold seats in KeralaIrikkur: While Left parties were undefeatable from this seat in the first four Assembly polls from 1957 to 1977, Congress hasn't lost this seat since 1977. KC Joseph won this seat for a record eight consecutive terms from 1982 to 2016.Kannur / Cannanore: The seat was a Congress bastion from 1987 to 2011. In the 1982 elections, it was won by the Independent candidate P Bhaskaran with the support from the Congress.Manjeri: This seat in Malappuram district has been a fortress of Indian Union Muslim League (IUML). The UDF ally hasn't lost from here since 1967. Before that, the Congress had won from here in 1957 and 1960.Malappuram: No party has been able to defeat IUML from this seat since the first election in 1957. It must be noted that IUML candidate in the 1957 polls, K. Hassan Gani, contested as an Independent.Kondotty: This is another Assembly seat from the Malappuram district that has been undisputedly won by IUML since the first Kerala state polls in 1957.Tirurangadi: Again, this is a seat from Malappuram district that has always elected an IUML candidate. Congress' AK Antony briefly represented this constituency after a 1995 bypoll, when he was called from Rajya Sabha to take over the state's chief ministership from K Karunakaran.Tanur: This is the fifth Malappuram seat that has had a total monopoly of IUML since the first elections.Changanassery / Changanacherry: This seat has been consecutively won by UDF allies since 1970 – by Kerala Congress from 1970 to 1982 and then by Kerala Congress (Mani) from 1991 onwards. CF Thomas won a record nine back-to-back elections from here from 1980 to 2016.Puthupally: This seat has been loyal to Congress, or more aptly, Congress leader Oommen Chandy. No one had been able to defeat Chandy from Puthupally in the 12 consecutive elections from 1970 onwards. Since 1957, Congress has lost just one Assembly poll from this constituency – in 1967 to CPI(M). Currently, Puthupally is represented by Oommen Chandy's son Chandy Oommen.Pala / Palai: It has been a sure-shot UDF seat since it was formed in 1967. Pala was the bastion of Kerala Congress (Mani) founder KM Mani, who remains the longest-serving member of the Kerala Legislative Assembly, having continuously represented the Pala constituency from its inception in 1967 until his death in 2019. Currently, this seat is held by Kerala Democratic Party.2026 Kerala Elections: Will the Duopoly of LDF and UDF Retain Their Strongholds?Kerala was the first Indian state that elected a non-Congress government – a CPI government in the 1957 Assembly polls. This was also Kerala's first elections after it formed as a separate state following the States Reorganisation Act, 1956. Since then, the state has seen a political duopoly with power rotating between CPI(M)-led LDF and Congress-led UDF. Currently, it remains the only Indian state that has a Left government at its helm.The upcoming 2026 Assembly elections may see BJP emerging as a third player. While the saffron party has historically won just one Assembly seat in the state (from Nemom or Thiruvananthapuram West in 2016 elections), it's recent political victories in the state – Thiruvananthapuram Municipal Corporation in 2025 and Thrissur Lok Sabha seat in 2024 – offers an indication of BJP's growing influence in a number of seats. Its total vote share % has consistently grown in the last four Kerala Assembly elections – from 4.75% in 2006 to 11.3% in 2021. However, increased vote share doesn't translate into Assembly wins, especially in a state like Kerala where LDF and UDF has dense grassroots networks built over decades through trade unions, cooperatives, and local self-government institutions.