We investigated political polarization among the 28284 candidates in the Finnish municipal election who ran for municipal council in 2012, 2017, or both, and had responded to a Voting Advice Application. Our results revealed political polarization in terms of both conversion (longitudinal analysis, n = 6643) and recruitment (cross-sectional comparison of first-time candidates, n = 13054). The populist radical-right Finns Party became even more anti-refugee, and the pro-refugee Green League became even more pro-refugee. The Finns Party, in particular, has constructed the Green League as their enemies, which could explain why the Finns Party moved in an anti-environmental direction, as well as the increased issue-alignment between refugee-attitudes and environmental attitudes. We also observed increased within-party homogeneity in almost all parties. In the discussion, we focus on the nature of the association between refugee and environmental attitudes.