Pew: Democrats Crushing Republicans in Party Identification Advantage

Kicking off its "Convention Backgrounder" [PDF], the Pew Center for the People and the Press says:

As the 2008 conventions approach, the Democratic Party's advantage in party identification remains as large as it has been over the past two decades, and the Democratic Party's image remains substantially more positive than the GOP's. The Democrats have a 13-point lead in party affiliation (51% vs. 38%) among registered voters, when independents who "lean" to either party are included. Four years ago, the Democrats held only a slim 47% to 44% lead by this same measure.

Over the past four years, the Democrats' gains in party affiliation among younger voters have been particularly striking. In 2004, the Democrats had a 10-point lead among 18-29 year olds (50% to 40%); this more than doubled, to 22 points (55% to 33%), in polling conducted between January and August of 2008.

And while Democratic gains have occurred across all income and education groups, the change from 2004 is particularly notable among middleincome voters. In 2004, Americans with household incomes between $30,000 and $75,000 tilted Republican (48% Republican/lean Republican, 44% Democrat/lean Democrat). Today, the Democrats have built a substantial 14-point lead among these voters (53% to 39%).