This Hindustan Times article quotes a 2015 IDFC Institute finding to discuss the need for midterm legislative assembly elections in order to facilitate federalism. The article states:
"Midterm polls also address the most significant criticism of simultaneous elections—their potential to undermine federalism. An IDFC institute report concludes: 'On average, there is a 77% chance that the Indian voter will vote for the same party for both the State and Centre when elections are held simultaneously.'"
Read the full article here.