Hominid Views

A recent post got me thinking about party affiliation. Specifically, I was wondering how party affiliation has changed over the last couple of years. Over this time, the Bush administration has tarnished the Republican brand in so many ways. Has this translated into a loss of Republican identity?

An important follow-up issue (for me, anyway) is the changes in Washington state. We have a somewhat wacky brand of Republicanism here. My impression is that the Washington state Republican party has moved significantly to the right to such an extent that the moderate Republican in Washington state seems like an endangered species.

A number of recent presidential approval polls include information on party affiliation. The following table summarizes the results of polls taken in July that offer party affiliation numbers. All polls are national except the last one that is specific to Washington State:

Since polls use different methods and questions, the difference between the two party identities is a more suitable measure than direct percentage comparisons between parties. The most recent polls show a 7% to 12% advantage to Democrats.

Unsurprisingly, Washington state is much “bluer” than the U.S. But the 19% spread in the most recent SurveyUSA poll is astonishing. Can it be that only 21% of Washington state voters identify themselves as Republican? I’ll take that up below.

It is difficult to make much of these numbers by looking at a single point in time. It might be, for example, that there are alway more people willing to identify as Democratic than Republican. To test this idea we need a time series.

Two polling firms Rassmussen Reports and Washington Post/ABC make historical information on party affiliation readily available.

The following two graphs show the change over time in party affiliation. The first graph uses a huge sample so there is very little sampling error. The second graph is based on small samples, so the sampling error causes a lot of bouncing.

The pattern is pretty clear. Identity as a Democrat has been pretty stable over time, whereas Republican identity has declined pretty significantly.

With a bit of squinting, you can see that the red line being mirrored by the green line. In other words, at the national level, people abandoning the Republican party tend to identify themselves as either independent or “other.” This is largely good news for Democrats, although I am sure they would prefer to see their numbers climb as people abandon the G.O.P. There is not much evidence for that right now.

(Update. This is clearly seen in the correlation coefficients: For the Rasmussen data, between Democratic and Republican r = 0.33, Democratic and independent r = -0.63, and Republican and independent r = -0.94. For the Washington Post–ABC data, the correlation between Democratic and Republican r = -0.44, Democratic and independent r = -0.33, and Republican and independent r = -0.54. Even with the nosier data, the strongest [negative] relationship exists between Republicans and independents.)

Washington state shows a pattern that differs from the national pattern:

Both Republican and Independent identity have declined since about the time of the election contest. The fraction of people who identify as Democrats is clearly increasing over time.

(Update. The correlation coefficients between Democratic and Republican r = 0.28, Democratic and independent r = -0.51, and Republican and independent r = 0.57. Democrats increase as independents decrease and Republicans decrease as independents decrease.)

Here are what the spreads look like at the national level for the three data sources:

Clearly, Democrats in Washington state are gaining gound on Republicans at a much greater rate than is seen nationally. The difference in Washington is that either ex-Republicans or ex-independents (or both) are actively switching to a Democratic identity. Nationally, the switch is away from a Republican identity to an independent identity.

Hey…I’m not all that surprised given the regular feast of stunts coming from the Republican party in Washington state.