[masklinn]

> The parties lined up more closely with longstanding ideological and cultural divides.

They don't though, for instance the dixiecrats ultimately had to choose between (to use the political compass's axis) left or authoritarianism with no party providing both. I'm sure there are left-authoritarian or right-libertarian voters in either main party which have to choose which they value most, unable to vote for any party which actually represents them as US politics puts them not just on a linear axis but on a completely bipolar one.