I’ve written recently on this blog about political polarization, noting several factors that point to its rise: (a) there has been an increase in ideological sorting among the parties, with conservatives being more closely identified with the Republican party and liberals more closely identified with the Democratic party; (b) partisan identification is a better predictor of vote choice than it was several decades ago; (c) partisan sentiment for the other side has been turning negative; (d) job approval of recent presidents has fallen more starkly along partisan lines in recent years.
