The main objections to my diary "Center-Left Nation: Congress Since WWII" seemed to be two-fold: first that I was only using a single data source. Second, more significantly, that I was making an argument that ignored the racism of the Southern Dems. My answers were that (1) You only need one data source to disprove a thesis ("center-right nation"), and advance (not prove) another ("center-left nation"); (2) It was still true in the aggregate, as shown, for example, by the Congressional DW-Nominate scores.
I stand by those answers, but of course, they don't need to be the last word. And, indeed, they shouldn't be the last word. Hence, a look at party ID since 1972, from the General Social Survey (GSS). It should be noted that the figures here--which include partisan leaners--are not as strikingly Democratic as those from Pew, which is also a very reputable pollster, and I have no explanation for the discrepancy. But GSS figures are available going much further back.
(GSS polls not taken every year, see tables below for exact dates.)
So, the Democrats have lost their crushing 2-1 advantage enjoyed in the early 70s, but still have maintained an edge in every GSS poll since that time. And as for arguments about Southern racist Dems, well, that's what God made regional crosstabs for...
STATE BLOGS
