Party ID Updates

Legacy blog posts Weighting by Party

Here is another quick update on some interesting releases over the last week or so on the subject of party identification from Harris and Gallup.   Two new reports – based on a full year’s worth of data – show a slightly greater Democratic advantage in 2005 than 2004, however similar data from the Pew Research Center shows no such trend.

  • Harris Interactive released their annual review of the long term trend in party identification and self-reported ideology.   Their conclusion, based on rolling together data from 4,945 US adults interviewed by telephone during 2005:  36% of Americans identified as Democrats (up from 34% in 2004) and 30% identified as Republicans (down from 31% in 2004).  The six point Democratic edge is "the largest lead since 2000."

The table showing 36 years of data on party identification is well worth the click, and worth comparing to a similar table of party ID results from American National Election Studies conducted in even numbered years since 1952 by the University of Michigan. 

  • Gallup released their own compilation based on their massive pool of 42,431 interviews conducted among US adults during 2005 (and the report appears to be free to all).  The report provides the results to the root party identification question for 2005 only (33% Republican, 33% Democrat).  They provide trended data based on the combined percentage of partisans plus those who initially identify as independents but say the "lean" to one of the parties on a follow-up question. 

Among those who identify or lean to one of the parties, their results also show a growing Democratic advantage in 2005. The Democratic edge increased from a margin of 2.7 percentage points in 2004 (47.9% to 45.2%) to 4.5 points (47.% to 43.2%) in 2005.  Jeff Jones report also provides party identification data for all 50 states. 

  • The Pew Research Center also provides annualized results for party identification on the "topline" questionnaire it releases with every survey, but only for the root party ID question (not for "leaners"). Their results show no change in party identification from 2004 to 2005.  In both years, 33% identified as Democrats, 30% as Republicans.

Keep in mind that the Michigan/Harris version of the party ID question differs slightly from the one used by Gallup.

Michigan and Harris ask:  Generally speaking, do you consider yourself a Republican, a Democrat, an independent or what?

Gallup asks:  In politics, as of today, do you consider yourself a Republican, a Democrat, or an Independent?

As noted here before, although the political scientists continue to debate the issue, some have produced evidence that the Gallup version allows for short term variation.

PS:  Occasional MP commenter DemFromCt has posted thoughts on what all of this might mean for Democrats on the Next Hurrah

Mark Blumenthal

Mark Blumenthal is political pollster with deep and varied experience across survey research, campaigns, and media. The original "Mystery Pollster" and co-creator of Pollster.com, he explains complex concepts to a multitude of audiences and how data informs politics and decision-making. A researcher and consultant who crafts effective questions and identifies innovative solutions to deliver results. An award winning political journalist who brings insights and crafts compelling narratives from chaotic data.