Ed Morrissey of Captains Quarters blog looks at partisanship in Congress and arrives at something of a surprising conclusion Ed examined the frequency with which members of Congress voted with their own party:

[T]he Democrats take nine of the top ten partisan spots, as well as scoring 8 points higher in partisanship as a party. The lone Republican ties for first, though:

100% - Charlie Norwood (R-GA)
100% - Nancy Pelosi (D-CA)
99.7% - Nita Lowey (D-NY
99.4% - Juanita Millender-McDonald (D-CA)
99.1% - Carolyn Maloney (D-NY)
98.9% - Xavier Bacerra (D-CA)
98.7% - Diana DeGetter (D-CO)
98.6% - Gary Ackerman (D-NY)
98.6% - Hilda Solis (D-CA)
98.6% - Ellen Tauscher (D-CA
98.6% - Al Wynn (D-MD)

Of course, Norwood is dead, and has been since February (h/t: The Anchoress). After Norwood, the next Republican comes in at 94.8%. JoAnn Davis (R-VA) has only cast 134 votes, however, as she has missed significant time while fighting a recurrence of breast cancer. She comes in at #174 on the list of partisans -- which means that Democrats occupy all of the previous 173 slots, of those among the living, anyway.

In comparison, Republicans occupy all of the ten positions for the least partisan Representatives.