Gallup put out an analysis of daily tracking data this week that was designed to establish that Asian-Americans are the most liberal U.S. ethnic group. But as Matt Yglesias immediately noted, what the analysis really does is to call into question the entire "liberal-moderate-conservative" self-identification spectrum in public opinion research.

Gallup's numbers for African-Americans show this rather emphatically: 24% call themselves liberals, 42% call themselves moderates, and 29% call themselves conservatives. By this measurement, African-Americans are a "center-right" bloc of voters. Yet the same survey notes that African-Americans self-identify as Democrats (or as Democratic "leaners") by a margin of 83% to 8%. And despite many years of conservative hopes and dreams for a rightward trend among African-Americans, they consistently represent the most solidly "liberal" category of voters by any measurement other than ideological self-identification.

In other words, as many of us have been saying for years, the L-M-C typology for ideological self-identification is deeply flawed and of limited utility. Yet an astonishing edifice of "analysis," commentary, and political rhetoric has been built on this shaky foundation, most recently the claim that Barack Obama is defying a "center-right nation" by trying to implement his campaign platform. It's time to retire it or replace it.