Not sure how we missed this, but Gallup has put up detailed demographic cross-tabulations based on the Gallup Daily tracking (that's the survey showing a four point lead for Barack Obama as of yesterday, not the USA Today Gallup poll that applied the "likely voter" screen and has been a source of controversy this week).
Here are descriptions and links just received via email from Gallup:
Gallup now has available online extensive data breaking out support for the presidential candidates within demographic, partisan, ideological, and regional subgroups.
The data are updated each Wednesday -- based on more than 6000 Gallup Poll Daily interviews conducted each week – and available here: http://www.gallup.com/poll/election2008.aspx. Importantly, the analyses can now be trended back through the week of June 9-15, showing the pattern of support within subgroup across time.
Candidate Support by Gender
Candidate Support by Gender Among Whites
Candidate Support by Age
Candidate Support by Region
Candidate Support by Race
Candidate Support by Education
Candidate Support by Education Among Whites
Candidate Support by Political Party
Candidate Support by Political Party Among Whites
Candidate Support by Political Party and Ideology
Candidate Support by Political Party and Ideology Among Whites
Candidate Support by Church Attendance Among Whites
Candidate Support by Marital Status
Candidate Support by Marital Status and Gender
Candidate Support by "Red," "Purple," and "Blue" States