I notice Ken Salazar of Colorado is not on your list. Did he vote for Roberts? And here I've been thinking he's the scum of the earth...
http://www.senate.gov/legislative/LIS/roll_call_lists/roll_call_vote_cfm.cfm?congress=109&session=1&vote=00245
Salazar voted for Roberts. Probably afraid of conservative constituents in Colorado. Other Senate liberals did the same, such as Bill Nelson of FL, who takes his cues from Kennedy and H. Klinton most of the time.