Congressional Quarterly Inc., Congressional Quarterly Weekly Report (copyright data source

http://www.cq.com/

Through 2002, Congressional Quarterly Inc., Congressional Quarterly Weekly Report (copyright).
Thereafter, Office of the Clerk, Statistics of the Presidential and Congressional Election, June 7, 2005.
INTERNET LINK
http://www.cq.com/
http://clerk.house.gov/member_info/election.html
referenced on dataset section 2004 (#3)

Vote Cast for United States Representatives by Major Political Party--Congressional

The Statistical Abstract files are distributed by the US Census Department as Microsoft Excel files. These files have data mixed with notes and references, multiple tables per sheet, and, worst of all, the table headers are not easily matched to their rows and columns. A few files had extraneous characters in the title. These were corrected to be consistent. A few files ...
Free