The following graph is taken from the Pew Report linked by Pajamas Media.
It's hard to believe that 50% self-identify as Democratic/leaning. But then again, polls have been "oversampling" Democrats by about that margin and perhaps they are not fudging the data but merely reflecting what they see as the fraction of Democrats in the country. Looking at the report, the trend seems to be due to a decrease in the number of folks identifying as Republican and an increase in the number of Independents leaning Democratic. The number of self-identified Democrats has remained constant at about 33%. Hmm. Wonder if Nancy Pelosi is indeed misjudging the public or if she is onto something. We shall see. Much could depend on perceived success in Iraq and how the media reports it.