No, I'm saying that the description that polarization was absent is wrong.

I'm also saying alignment of the axis of differentiation between the major parties in a two-party system and the salient divides in society makes it easier for people to make meaningful choices, and feel they are doing so, by voting.

When there are sharp polarizing social/political divides, as there were over many issues in the 1950s, and they are not reflected in the divides between the parties (as they often weren't in the 1950s), then the government cannot represent the people because the people cannot express their preferences on important issues by voting.