Over the first four months of 2009, the Republican Party has continued to lose adherents. Interviews with over 7,000 respondents nationwide so far this year found fewer than a quarter (23%) of the combined total identifying themselves as Republicans. This is down from 25% in 2008, and from 30% in 2004. In total, the GOP has lost roughly a quarter of its base over the past five years.
But these Republican losses have not translated into substantial Democratic gains. So far in 2009, 35% of adults nationwide identify as Democrats, about the same as in 2008 (36%). While GOP identification has fallen seven points since 2004, the Democrats have gained only two points over that period. Instead, a growing number of Americans describe themselves as independents, 36% in 2009 compared with just 32% in 2008 and 30% in 2004.
Looking at the individual monthly surveys since December suggests that both political parties are facing declining membership in the wake of an engaging election cycle. In the Pew Research Center's April 2009 survey, 33% identified as Democrats, down from 39% in December 2008. Over the same period, the share calling themselves Republicans has fallen from 26% to 22%. By contrast, the number of independents has risen from 30% in December to 39% now. While it is not unusual for Republican and Democratic identification to grow over the course of an election and subside afterward, the magnitude of these changes is noteworthy.
In announcing his change in party affiliation from Republican to Democrat yesterday, Pennsylvania Sen. Arlen Specter mentioned the changing composition of his state as a consideration. Across a typical year the Pew Research Center conducts well over 1,000 interviews in Pennsylvania, including 384 in the first four months of 2009. The data, so far, support Sen. Specter's contention. When he last ran for his seat in 2004, 38% of Pennsylvanians said they were Democrats, while 34% identified as Republican. This year, the share identifying as Democrats is the same 38%, but only 27% call themselves Republicans. What had been a slim four-point Democratic identification advantage is now an eleven-point advantage.
The pattern of partisan change in recent years has been remarkably consistent across the nation. Since 2004, the GOP has lost at least five points in party identification in every region of the nation. Meanwhile, Democratic identification in 2009 is either at or just slightly above 2004 levels. The Northeast stands out from other parts of the country not for the magnitude of the shift, but the overall balance in favor of Democrats. Even in 2004 -- when there were nearly as many Republicans as Democrats in the rest of the country -- Democrats held a substantial 35% to 26% advantage in Northeastern states. That advantage has widened to a nearly two-to-one edge (38% to 20%) in 2009.