"Dems Maintain 8.3 Percent Affiliation Edge
by Jonathan Singer, Wed Jan 06, 2010 at 09:00:49 PM EST
Gallup has also released data on the partisan affiliation of American adults that buttresses the sentiment written about by Politico (among others) that the Democrats' majorities in Congress aren't yet realistic threatened.
Through the 2009 calendar year, Gallup found that Americans allied with the Democratic Party over the Republican Party by a 49.0 percent to 40.7 percent margin -- or an 8.3 percentage point edge for the Democrats. While this is down a net 3.4 percentage points from 2008, it still represents a major difference from just a few years ago when the Republicans were in the majority. Indeed, during 2004, when the Republicans posted their largest congressional majorities in nearly 60 years, the Democratic advantage among American adults was a paltry 2.7 percentage points (47.9 percent to 45.2 percent). Putting these numbers together, the Democrats' standing with the American public is still a net 5.6 percentage points better than it was five years ago.
Putting the Gallup partisan affiliation numbers up against the net nationwide vote for the House of Representatives over the past three cycles, it appears there is at least somewhat of a correlation (with the top line representing the net Democratic affiliation edge and the bottom line representing the net Democratic House vote edge or, in the case of the 2004 elections, disadvantage):
(Sources: Partisan affiliation data from Gallup; nationwide House votes from 2004, 2006, and 2008 from Wikipedia.)
As you can see, the past two cycles, in particular, have seen a close correlation between partisan affiliation and the nationwide House vote, with Democratic affiliation edges corresponding with with actual vote edges of about 3 percentage points less (exactly 3.0 2.3 percentage points in 2006 and 2.9 percentage points in 2008). (The spread between partisan affiliation and the nationwide House vote in 2004 was wider -- 9.1 5.3 percentage points.)
This clearly is not a perfect correlation -- but it's not a terrible one, either. And it makes intuitive sense: As more Americans identify with the Democratic Party, the Democrats tend to earn a greater share of the nationwide House vote.
This isn't necessarily predictive of the future. That said, the Democrats' affiliation edge in 2009 -- 8.3 percentage points -- looked a lot more like their edges of 10.2 percentage points in 2006 and 11.7 percentage points in 2008 (when they won) than their edge of 2.7 percentage points in 2004 (when they lost). And it's hard to see how that could be bad news.
(NOTE: This post has been updated with better numbers.)"