This article studies electoral competition in a model of redistributive politics with deterministic voting and heterogeneous voter loyalties to political parties. We construct a natural measure of `party strength' based on the sizes and intensities of a party's loyal voter segments and demonstrate how party behavior varies with the two parties' strengths. In equilibrium, parties target or `poach' a strict subset of the opposition party's loyal voters: offering those voters a high expected transfer, while `freezing out' the remainder with a zero transfer. The size of the subset of opposition voters frozen out and, consequently, the level of inequality in utilities generated by a party's equilibrium redistribution schedule is increasing in the opposition party's strength. We also construct a measure of `political polarization' that is increasing in the sum and symmetry of the parties' strengths, and find that the expected ex-post inequality in utilities of the implemented policy is increasing in political polarization.
Kovenock, Dan, and Brian Roberson. "Electoral poaching and party identification." Journal of Theoretical Politics 20.3 (2008): 275-302.