It seems like there's someone who publishes ratings based on the roll call votes of the House and Senate for nearly everything nowadays. But nobody publishes ratings based on
partisanship (how often a member of Congress votes their own party's party line) and
bipartisanship (how often a member of Congress votes the other party's party line).
Below the fold is a list of every member of Congress's Bipartisan Index (CBI) and the methodology I used to come up with it
CBIs as of 3/22/06 for the 109th Congress
Ranked from Highest to Lowest by Party
Chafee[R]: 0.545 Nelson(NE)[D]: 0.532
Snowe[R]: 0.445 Baucus[D]: 0.238
Collins[R]: 0.402 Carper[D]: 0.224
DeWine[R]: 0.304 Landrieu[D]: 0.224
Specter[R]: 0.303 Conrad[D]: 0.199
Coleman[R]: 0.238 Pryor[D]: 0.175
Smith[R]: 0.18 Lincoln[D]: 0.171
Voinovich[R]: 0.169 Johnson[D]: 0.159
Talent[R]: 0.153 Nelson(FL)[D]: 0.157
Lugar[R]: 0.148 Salazar[D]: 0.142
McCain[R]: 0.138 Byrd[D]: 0.141
Warner[R]: 0.137 Bingaman[D]: 0.129
Sununu[R]: 0.122 Kohl[D]: 0.1
Thune[R]: 0.120 Biden[D]: 0.097
Hutchison[R]: 0.1 Lieberman[D]: 0.097
Gregg[R]: 0.086
Dorgan[D]: 0.095
Murkowski[R]: 0.079 Bayh[D]: 0.086
Burns[R]: 0.073 Inouye[D]: 0.082
Santorum[R]: 0.073 Jeffords[I]: 0.081
Alexander[R]: 0.072 Feinstein[D]: 0.079
Domenici[R]: 0.072 Rockefeller[D]: 0.078
Coburn[R]: 0.068 Cantwell[D]: 0.076
Ensign[R]: 0.068 Reid[D]: 0.071
Graham[R]: 0.065 Schumer[D]: 0.061
Stevens[R]: 0.064 Dodd[D]: 0.055
Roberts[R]: 0.061 Stabenow[D]: 0.05
Dole[R]: 0.060 Akaka[D]: 0.046
Craig[R]: 0.058 Clinton[D]: 0.044
Vitter[R]: 0.058 Wyden[D]: 0.043
Martinez[R]: 0.058 Feingold[D]: 0.04
Bond[R]: 0.057 Menendez[D]: 0.04
Hagel[R]: 0.057 Murray[D]: 0.039
Thomas[R]: 0.055 Dayton[D]: 0.038
Shelby[R]: 0.054 Corzine[D]: 0.034
Inhofe[R]: 0.051 Levin[D]: 0.032
Burr[R]: 0.05 Leahy[D]: 0.029
Lott[R]: 0.048 Kerry[D]: 0.025
Enzi[R]: 0.047 Obama[D]: 0.025
Hatch[R]: 0.047 Reed[D]: 0.021
Frist[R]: 0.046 Harkin[D]: 0.018
Allen[R]: 0.046 Boxer[D]: 0.015
Crapo[R]: 0.046 Lautenberg[D]: 0.014
Grassley[R]: 0.046 Sarbanes[D]: 0.014
Bennett[R]: 0.044 Mikulski[D]: 0.011
Chambliss[R]: 0.043 Durbin[D]: 0.011
Isakson[R]: 0.043 Kennedy[D]: 0.004
Cochran[R]: 0.039
Cornyn[R]: 0.036
DeMint[R]: 0.032
Brownback[R]: 0.032
Allard[R]: 0.025
Sessions[R]: 0.021
Bunning[R]: 0.018
Kyl[R]: 0.018
McConnell[R]: 0.011
Ranked Alphabetically
Akaka[D]: 0.046
Alexander[R]: 0.072
Allard[R]: 0.025
Allen[R]: 0.046
Baucus[D]: 0.238
Bayh[D]: 0.086
Bennett[R]: 0.044
Biden[D]: 0.097
Bingaman[D]: 0.129
Bond[R]: 0.057
Boxer[D]: 0.015
Brownback[R]: 0.032
Bunning[R]: 0.018
Burns[R]: 0.073
Burr[R]: 0.050
Byrd[D]: 0.141
Cantwell[D]: 0.076
Carper[D]: 0.224
Chafee[R]: 0.545
Chambliss[R]: 0.043
Clinton[D]: 0.044
Coburn[R]: 0.068
Cochran[R]: 0.039
Coleman[R]: 0.238
Collins[R]: 0.402
Conrad[D]: 0.199
Cornyn[R]: 0.036
Corzine[D]: 0.034
Craig[R]: 0.058
Crapo[R]: 0.046
Dayton[D]: 0.038
DeMint[R]: 0.032
DeWine[R]: 0.304
Dodd[D]: 0.055
Dole[R]: 0.060
Domenici[R]: 0.072
Dorgan[D]: 0.095
Durbin[D]: 0.011
Ensign[R]: 0.068
Enzi[R]: 0.047
Feingold[D]: 0.040
Feinstein[D]: 0.079
Frist[R]: 0.046
Graham[R]: 0.065
Grassley[R]: 0.046
Gregg[R]: 0.086
Hagel[R]: 0.057
Harkin[D]: 0.018
Hatch[R]: 0.047
Hutchison[R]: 0.1
Inhofe[R]: 0.051
Inouye[D]: 0.082
Isakson[R]: 0.043
Jeffords[I]: 0.081
Johnson[D]: 0.159
Kennedy[D]: 0.004
Kerry[D]: 0.025
Kohl[D]: 0.100
Kyl[R]: 0.018
Landrieu[D]: 0.224
Lautenberg[D]: 0.014
Leahy[D]: 0.029
Levin[D]: 0.032
Lieberman[D]: 0.097
Lincoln[D]: 0.171
Lott[R]: 0.048
Lugar[R]: 0.148
Martinez[R]: 0.058
McCain[R]: 0.138
McConnell[R]: 0.011
Menendez[D]: 0.04
Mikulski[D]: 0.011
Murkowski[R]: 0.079
Murray[D]: 0.039
Nelson(FL)[D]: 0.157
Nelson(NE)[D]: 0.532
Obama[D]: 0.025
Pryor[D]: 0.175
Reed[D]: 0.021
Reid[D]: 0.071
Roberts[R]: 0.061
Rockefeller[D]: 0.078
Salazar[D]: 0.142
Santorum[R]: 0.073
Sarbanes[D]: 0.014
Schumer[D]: 0.061
Sessions[R]: 0.021
Shelby[R]: 0.054
Smith[R]: 0.180
Snowe[R]: 0.445
Specter[R]: 0.303
Stabenow[D]: 0.050
Stevens[R]: 0.064
Sununu[R]: 0.122
Talent[R]: 0.153
Thomas[R]: 0.055
Thune[R]: 0.120
Vitter[R]: 0.058
Voinovich[R]: 0.169
Warner[R]: 0.137
Wyden[D]: 0.043
Methodology
Note: Jim Jeffords and Bernard Sanders are considered as Democrats for the purposes of determining the Congressional Bipartisan Index.
A vote was considered to be a partisan vote if it met one of the following 2 criteria
- At least 1/2 of the Republicans voting voted YEA and at least 1/2 of the Democrats voting voted NAY.
- At least 1/2 of the Democrats voting voted YEA and at least 1/2 of the Republicans voting voted NAY.
A Senator was considered to have cast a
bipartisan vote if they did not vote with the majority of the members of their party (i.e. they voted YEA when the majority of those Senators in their party voted NAY).
The Congressional Bipartisan Index is calculated by dividing the number of times the Senator cast a
bipartisan vote by the total number of
partisan votes they voted either YEA or NAY on (i.e. partisan votes for which they are either recorded as having voted PRESENT on or as not having voted on are not counted).
Update: I created a modified version of the algorithm. This version disregards H RES roll call votes, since those are either Motions to suspend the rules and pass, in which case they pretty much never qualify as partisan votes, or they are procedural votes, in which case the votes have to do with the person's party rather than their position on any issue [i.e. the party line] (parties expect their members to vote the party line on procedural issues; John Shadegg was kicked off the assistant whip team recently for failing to do so on one vote).
I wrote a Java program to do the actual tallying for me (I obtained the roll call vote data from www.govtrack.us, because the format there is easier to parse than the format given at senate.gov). If anyone's interested, I suppose once I've generalized and improved the program and made it more user-friendly so that I'm not embarassed by it, I can post the code here. (Yes, I know that Java was not the most efficient language to use, but frankly, I don't care).