The Delhi assembly elections of 2025 have marked a significant shift in voter behaviour. Aam Aadmi Party (AAP), which enjoyed massive support in 2015 and 2020, witnessed a considerable decline in its median votes across multiple categories. Meanwhile, the Bharatiya Janata Party (BJP) made substantial gains, and the Indian National Congress (INC) remained relatively weak but showed minor improvements. This data-driven report explores which voter segments left AAP and where they went.
We chose to analyse the median vote count rather than the average because the median provides a better representation of ‘typical’ constituency performance without being skewed by extreme values. Given that some constituencies may experience unusually high or low vote counts due to specific local factors, the median ensures that our analysis reflects the general trend across all seats, making the insights more reliable.
AAP’s median vote count has seen a drastic decline in 2025, reversing its upward trend from previous elections. In 2015, AAP secured 64,394 votes per constituency, which increased to 67,731 in 2020—showing modest growth across most constituencies. However, by 2025, AAP’s median vote count fell sharply to 54,545, marking a 19.5% decline from 2020 and a 15.3% drop from 2015. This indicates AAP has lost both its recent gains and part of its original support base. The decline of over 13,000 median votes per constituency represents a widespread setback rather than isolated losses.
BJP, by contrast, has shown steady growth across all three elections. Its median vote count rose from 40,908 in 2015 to 48,824 in 2020 – a 19.4% increase. This upward trend continued in 2025, with BJP reaching 57,891 votes per constituency, an 18.6% rise from 2020 and a 41.5% increase from 2015. These numbers show BJP has steadily built its voter base over a decade rather than benefiting from a sudden shift in 2025. The parallel between AAP’s losses and BJP’s gains suggests most of AAP’s former voters have moved to BJP.
Congress remains a marginal player, despite modest recovery in 2025. From a median of 10,440 votes per constituency in 2015, it plummeted by nearly 60% to 4,280 votes in 2020. While 2025 brought a slight increase to 6,741 votes – 57.5% higher than 2020 but still 35.4% below 2015 levels – Congress has attracted only a small portion of disillusioned AAP voters. The party remains far below its historical support levels, with most of its traditional base now aligned with either AAP or BJP.
In General/Open category seats, AAP’s performance peaked in 2020 before declining sharply in 2025. AAP’s median votes in General seats rose slightly from 61,782 in 2015 to 63,646 in 2020, showing a stable voter base. However, by 2025, AAP’s votes dropped to 53,690 – a 15.6% decline from 2020 and a 13% drop from 2015. This decline indicates AAP lost both its new 2020 voters and part of its original 2015 base.
BJP, meanwhile, has shown consistent growth in General seats across all three elections. Its median vote count increased from 43,464 in 2015 to 50,269 in 2020, and further to 61,192 in 2025. This represents a 21.7% increase from 2020 and a 40.7% growth from 2015, demonstrating BJP’s growing strength in General constituencies.
Congress remains a non-factor in General seats, despite slight improvements in 2025. The party’s median vote count plunged from 10,241 in 2015 to 4,638 in 2020 – a 54.7% decline. While votes increased to 6,656 in 2025, this remains well below 2015 levels. This pattern shows Congress has failed to reclaim its traditional voters, who have largely shifted to either AAP or BJP.
AAP’s performance in Dalit-heavy constituencies, including SC-reserved seats, showed steady growth from 2015 to 2020 before declining sharply in 2025. In SC-reserved seats, AAP’s median vote count rose from 70,054 in 2015 to 73,809 in 2020, demonstrating its ability to maintain and expand its Dalit voter base. However, this trend reversed in 2025 when AAP’s median vote share fell to 58,296 – a 21% decline from 2020 and a 16.8% drop from 2015. Similar patterns emerged in Dalit-majority constituencies. In areas with 20%+ Dalit population, AAP peaked at 68,348 median votes in 2020 before falling to 57,004 in 2025 – a 16.6% drop. The decline was even steeper in constituencies with 30%+ Dalit voters, where AAP’s vote count dropped from 74,154 in 2020 to 57,825 in 2025 – a 22% decline that fell below its 2015 performance.
BJP, meanwhile, has consistently expanded its presence in SC and Dalit-majority constituencies. In SC-reserved seats, BJP’s median vote count increased from 34,390 in 2015 to 44,038 in 2020, then climbed to 55,499 in 2025—representing a 61.4% increase over 2015 and a 26% rise from 2020. This growth continued in areas with 20%+ Dalit voters, where BJP’s vote count rose from 37,184 in 2015 to 54,092 in 2025 – a 45.5% increase. BJP’s most significant gains came in constituencies with 30%+ Dalit voters, where its vote count nearly doubled from 30,956 in 2015 to 55,985 in 2025. This 80.8% increase suggests a substantial shift of Dalit voters from AAP to BJP.
Congress has continued its long-term decline in Dalit constituencies, despite modest recovery in 2025. In SC-reserved seats, Congress’ median vote count plummeted from 10,512 in 2015 to 3,728 in 2020—a 64.5% drop. While votes increased to 7,201 in 2025, this remained 31.5% below 2015 levels. The pattern repeated in 20%+ Dalit seats, where Congress fell from 10,350 votes in 2015 to 4,073 in 2020, before slightly recovering to 6,348 in 2025. In 30%+ Dalit seats, Congress followed a similar trajectory, dropping from 9,144 votes in 2015 to 3,365 in 2020, then rising to 6,147 in 2025. Despite this modest recovery, Congress remains a distant third in Dalit-dominated constituencies.
AAP’s performance in Jat-influenced seats shows a clear decline over time. After securing 93,838 median votes in 2015, the party saw its numbers drop to 86,287 in 2020 – an 8% decrease. The decline accelerated in 2025, with votes plummeting to 76,687 – an 11.1% drop from 2020 and an 18.3% fall from 2015.
BJP, in contrast, has shown remarkable growth in Jat-dominated areas. Starting with 52,968 median votes in 2015, the party surged to 72,601 votes in 2020 – a 37% increase. This momentum continued into 2025, reaching 88,527 votes – marking a 21.9% rise from 2020 and a 67.2% increase from 2015.
Congress remains a minor player in Jat seats. From 10,123 median votes in 2015, the party’s support fell to 6,270 votes in 2020—a 38% decline. While 2025 brought a modest recovery to 8,902 votes, this remains below 2015 levels.
AAP’s performance in Sikh-influenced seats peaked in 2020 before dropping significantly in 2025. In 2015, AAP’s median vote count in Sikh seats was 57,180, rising to 62,103 in 2020 – an 8.6% increase. However, by 2025, AAP’s median votes fell to 52,134, representing a 16.1% drop from 2020 and an 8.8% decline from 2015. This decline indicates AAP lost both its 2020 gains and fell below its original 2015 support level in these constituencies.
BJP, by contrast, has shown steady growth in Sikh-influenced seats across all three elections. From 38,122 median votes in 2015, BJP increased slightly to 39,240 in 2020. The party then surged in 2025, securing 50,179 median votes – a 27.9% increase from 2020 and a 31.6% rise from 2015.
Congress has continued to decline in Sikh seats since 2015. From 9,423 median votes in 2015, Congress plummeted to 4,474 in 2020 – a 52.5% drop. The party fell further in 2025, securing only 3,862 median votes—a 13.7% decrease from 2020 and a 59% decline from 2015.
AAP remained dominant in Muslim-majority constituencies, though its vote count peaked in 2020 before declining in 2025. In seats where Muslims comprise over 40% of voters, AAP’s median votes increased from 57,118 in 2015 to 67,282 in 2020 – a 17.8% rise that showed strong Muslim voter consolidation. However, by 2025, votes dropped to 58,120 – a 13.6% decline from 2020, though still above 2015 levels. Similarly, in areas with over 30% Muslim voters, AAP’s votes surged from 57,913 in 2015 to 78,735 in 2020 – a 35.9% increase – before falling to 66,995 in 2025. This 14.9% drop from 2020 still left AAP 15.7% above its 2015 numbers, indicating it remains the preferred choice among Muslim voters despite losing some recent gains.
BJP continues to face challenges in Muslim-majority areas, though its vote share has grown steadily, especially in mixed-demographic constituencies. In seats with over 40% Muslim voters, BJP’s median votes rose from 23,241 in 2015 to 29,472 in 2020 – a 26.8% increase – before slightly declining to 27,181 in 2025. This represented a 7.8% drop from 2020 but remained 16.9% above 2015 levels. In areas with over 30% Muslim voters, BJP showed consistent growth, increasing from 35,348 votes in 2015 to 51,714 in 2020, and further to 56,592 in 2025 – marking a 60% rise since 2015. This suggests that BJP has been able to gradually expand its voter base in constituencies where the Muslim population is sizeable but not overwhelming, likely gaining support from non-Muslim residents in these areas. However, it remains non-competitive in constituencies where Muslim voters form an outright majority.
Congress, once the preferred party of Muslim voters, experienced a dramatic decline in 2020 followed by partial recovery in 2025. In constituencies with over 40% Muslim voters, Congress’s median votes plunged from 20,135 in 2015 to just 4,802 in 2020 – a 76.1% drop – as voters shifted to AAP. By 2025, Congress rebounded to 12,739 votes, marking a 165% increase from 2020 but still 36.7% below 2015 levels. The pattern was similar in areas with over 30% Muslim voters, where votes fell from 15,568 in 2015 to 4,963 in 2020, before recovering to 11,029 in 2025. While this recovery doubled its 2020 numbers, Congress remains well below its historical strength, with most of its former support still aligned with AAP.
In Purvanchali-influenced constituencies, AAP’s previous dominance has declined significantly in 2025. The party’s support among Purvanchali voters peaked in 2020, with median votes rising from 73,519 in 2015 to 80,854 in 2020. However, votes dropped to 64,254 in 2025 – a 20.4% decline from 2020. Similarly, in non-Purvanchali areas, AAP’s votes fell from 64,648 to 52,226 – a 19.2% decrease. While these losses were widespread, they were slightly more pronounced in Purvanchali areas, though AAP remains the strongest party in these constituencies.
BJP has steadily increased its presence in Purvanchali-influenced areas across three elections. Its median votes grew from 39,818 in 2015 to 57,461 in 2020 – a 44.3% increase – before reaching 58,217 in 2025, a modest 1.3% rise. In non-Purvanchali areas, BJP’s votes increased from 41,174 in 2015 to 46,919 in 2020, then to 57,565 in 2025.
Congress remains a minor player in Purvanchali areas, despite showing slight recovery in 2025. The party’s median votes in Purvanchali seats plunged from 9,450 in 2015 to 3,262 in 2020 – a 65.5% drop – as voters shifted to AAP and BJP. While votes rebounded to 6,561 in 2025, this remains 30.5% below 2015 levels. Non-Purvanchali seats followed a similar pattern: Congress fell from 10,558 votes in 2015 to 4,802 in 2020, before rising to 6,741 in 2025. Though this modest recovery indicates some voter discontent with AAP, Congress remains far from its former position of strength.
AAP’s vote share peaked across economic segments in 2020 but declined significantly in 2025, most notably in upper-class areas. AAP’s median votes in upper-class constituencies rose from 66,602 in 2015 to 69,679 in 2020, showing stable elite support. However, this collapsed to 38,395 votes in 2025 – a 44.9% decline from 2020 and a 42.3% drop from 2015 – marking the sharpest loss among all class groups. Middle-class constituencies followed a similar pattern: votes increased from 65,006 in 2015 to 69,947 in 2020, then fell to 52,297 in 2025 – a 25.3% drop from 2020. Even in lower-class constituencies, traditionally AAP’s stronghold, support declined significantly. Here, median votes rose from 58,229 in 2015 to 60,632 in 2020 but fell to 46,567 in 2025 – a 23.2% decline. These trends show AAP has lost broad appeal across all economic groups, with the steepest decline in wealthy areas.
BJP, meanwhile, has grown steadily across all class categories, particularly in upper and middle-class constituencies. In upper-class areas, BJP’s median votes increased from 43,464 in 2015 to 53,051 in 2020, then surged to 62,398 in 2025 – a 43.5% increase from 2015. The middle-class segment showed even stronger growth: from 39,272 votes in 2015 to 48,865 in 2020, then jumping to 62,788 in 2025 – a 59.8% increase from 2015. Lower-class areas, where BJP traditionally struggled, also shifted toward the party, though more gradually. Votes rose from 40,938 in 2015 to 44,256 in 2020, then climbed sharply to 56,858 in 2025 – a 38.9% increase from 2015. This growth shows BJP has successfully expanded beyond its traditional base, gaining support across all economic segments.
Congress, once dominant in upper and middle-class areas, collapsed in 2020 and made only modest recoveries in 2025. In upper-class constituencies, Congress’s median votes plunged from 10,720 in 2015 to 4,837 in 2020, before rising slightly to 6,823 in 2025 – still 36.3% below 2015 levels. Middle-class seats showed a similar decline: from 8,992 votes in 2015 to 4,085 in 2020, recovering partially to 6,782 in 2025. The party performed marginally better in lower-class areas, where votes fell from 10,766 in 2015 to 4,075 in 2020 before rising to 7,230 in 2025 – a 77.5% increase from 2020 but still 32.8% below 2015 levels. Congress remains a distant third across all economic segments, unable to reclaim its former position.
To understand the why and how behind these voter shifts, we must examine how different categories intersect rather than analysing them in isolation. Voter behaviour is shaped by multiple overlapping identities and influences – class, caste, religion, economic status, and regional factors. For example, did Dalit voters in lower-class areas move differently than Dalit voters in middle-class areas? Similarly, a Jat voter in a lower-class constituency may vote differently from a Jat voter in an upper-class area, showing how economic factors interact with caste dynamics. This analysis will be explored in the second part of this report.
