The polarisation of Hindu votes in the Muslim dominated areas helped the BJP gain in numbers in the Muslim dominated constituencies. The party's number grew from 6 in 2013 to 15 this year in the constituencies that are dominated by Muslims.
In Karnataka there are 33 constituencies which have a Muslim dominated population. The fact that the BJP performed well in these belts could be attributed to the fact that there was a split of Muslim votes between the Congress and JD(S) apart from the fact that the Hindu votes had polarised in favour of the party.
In the Muslim dominated constituencies, the Congress which had won 19 in 2013 managed 15 this year. The JD(S) won 3 as opposed to the five in 2013. The others drew a blank as opposed to the 4 they had won in the previous elections.
The BJP also performed well in those belts that were dominated by the Schedule Castes. Its tally was up from 11 in 2013 to 22 in 2018. There are 64 seats where there is a population of 15 per cent SCs.
In this seats it was expected that the BJP would perform badly owing to the widespread Dalit protests that had taken place across the country. However the BJP doubled its seats in these belts owing to several factors. Dr. Sandeep Shastri, leading political scientist says that the AHINDA agenda did not hold strongly for the Congress. The non-Kurubas and the OBCs moved towards the BJP. The left Dalits too have been unhappy with Siddaramaiah over the non-implementation of a proposal that recommended internal reservation for them. Overall the social coalition that the Congress tried to create backfired and ended up benefiting the BJP, he also says.
The other major factor was the return of B Sriramulu to the BJP. He was projected as the tallest leader among the tribals which helped the party score in these belts.
In the SC dominated belts, the Congress had won 36 in 2013, but in 2018 the number came down to 26. For the JD(S) the performance was almost same when compared to 2013. The party won 15 seats this year when compared to the 14 in 2013. The others tally came down from 3 in 2013 to 1 this year.
The big gains that the BJP made was in the mining region. From 4 in 2013, the party's tally rose to 15 this year. The mining region has 26 seats. For the Congress on the other hand the tally dropped from 18 in 2013 to 11 this year. The JD(S) which bagged 3 seats in 2013 drew a blank. The tally of the others too came down from 1 to 0 this year.
In the Lingayat dominated seats the BJP repeated its performance of 2008 by winning 38 seats. In 2013 the party won just 11. The disaster was for the Congress whose tally came down from 47 in 2013 to 21 this year. The JD(S) had bagged 11 in 2013 and its number dropped to 10 this year.