111th Senate Rank Ordering



Jeff Lewis and Keith Poole

27 December 2009


Below is the rank ordering of the 111th Senate. This ordering was produced by the Optimal Classification (OC) algorithm described in:

"Non-Parametric Unfolding of Binary Choice Data." Political Analysis, 8:211-237, 2000.

The scaling program that performs the rank ordering along with some examples can be downloaded from:

Optimal Classification (OC) Scaling Program Page

To see how OC works in one dimension, go to this page:

How Optimal Classification Works in One Dimension

To see how OC works in two or more dimensions, go to this page:

How Optimal Classification Works in Two or More Dimensions (Under Construction)

There were 397 roll calls cast in the 111th Senate as of 24 December 2009 of which 373 roll calls had at least 0.5% or better in the minority and were used in the scaling. The rank ordering is based upon these 373 roll calls. Note that tied ranks are allowed.

The overall correct classification is 94.3% with an aggregate proportional reduction in error of (APRE) .824. In the ordering below, the number just to the right of the Senator's name is the classification error and the number to the right of that is the total number of roll calls cast by the Senator. For example, placing Senator Durbin at the rank of 3.0 only resulted in 5 classification errors out of a total of 369 votes cast. The proportion correct is 364/369 = .986 (which is shown just to the left of the rank).

The two parties are perfectly separated in the liberal-conservative ordering.

(To obtain the latest 111th Senate Roll Call Matrix go to Jeff Lewis' Webserver. To obtain a Stata 7 version of the Roll Call Matrix go to the Data Download Page on this Server. )

(Two dimensional spatial maps of the last 50 Senate Roll calls are displayed here and the last 50 House Roll calls are displayed here.)

(Senators Clinton, Obama, and McCain are Compared Here.)

Ideological Rank Orderings of Recent Congresses: 111th House, 110th Senate, 110th House, 109th Senate, 109th House, 108th Senate, 108th House, 107th Senate, 107th House. For Parametric Measures go to the Data Download Page.

(The 110th Senate is the most polarized Senate since the end of Reconstruction.)

(Senator Feingold's seemingly "odd" rank of 57 is discussed here.)
 111 29147  6  VERMONT I SANDERS       19  370   0.949   1.000
 111 40704  5  RHODE I D WHITEHOUSE     5  362   0.986   2.000
 111 15021 21  ILLINOI D DURBIN         5  369   0.986   3.000
 111 14230 31  IOWA    D HARKIN         7  368   0.981   4.000
 111 14920  3  MASSACH D KERRY  JOHN    4  363   0.989   5.000
 111 29389 24  OHIO    D BROWN          3  365   0.992   6.000
 111 15408 52  MARYLAN D CARDIN         7  373   0.981   7.000
 111 14440 52  MARYLAN D MIKULSKI       2  332   0.994   8.500
 111 40903 21  ILLINOI D BURRIS         4  363   0.989   8.500
 111 14914 12  NEW JER D LAUTENBERG     3  371   0.992  10.500
 111 20735 13  NEW YOR D GILLIBRAND     7  353   0.980  10.500
 111 49308 73  WASHING D MURRAY        12  365   0.967  14.000
 111 39310 73  WASHING D CANTWELL      20  371   0.946  14.000
 111 15015 11  DELAWAR D CARPER        27  372   0.927  14.000
 111  4812 82  HAWAII  D INOUYE         5  370   0.986  14.000
 111 14709 23  MICHIGA D LEVIN  CARL    9  373   0.976  14.000
 111 29373 12  NEW JER D MENENDEZ       8  369   0.978  18.000
 111 29142  5  RHODE I D REED           6  368   0.984  18.000
 111 14400 82  HAWAII  D AKAKA          9  373   0.976  18.000
 111 15704  1  CONNECT D LIEBERMAN     30  361   0.917  21.500
 111 40901 11  DELAWAR D KAUFMAN       11  367   0.970  21.500
 111 14922 56  WEST VI D ROCKEFELLER    8  320   0.975  21.500
 111 14213  1  CONNECT D DODD           4  363   0.989  21.500
 111 40912  3  MASSACH D KIRK           0   85   1.000  24.000
 111 14858 13  NEW YOR D SCHUMER        5  373   0.987  25.000
 111 49300 71  CALIFOR D FEINSTEIN     13  371   0.965  27.000
 111 15011 71  CALIFOR D BOXER          8  370   0.978  27.000
 111 29732 23  MICHIGA D STABENOW      12  370   0.968  27.000
 111 40904 33  MINNESO D FRANKEN        6  164   0.963  29.000
 111 14871 72  OREGON  D WYDEN          8  368   0.978  30.000
 111 14307  6  VERMONT D LEAHY         11  366   0.970  32.500
 111 14912 66  NEW MEX D BINGAMAN      24  373   0.936  32.500
 111 40908 72  OREGON  D MERKLEY       12  372   0.968  32.500
 111 40906  4  NEW HAM D SHAHEEN       15  369   0.959  32.500
 111 14651 43  FLORIDA D NELSON        21  371   0.943  35.500
 111 15703 25  WISCONS D KOHL          16  373   0.957  35.500
 111 29924 66  NEW MEX D UDALL         12  370   0.968  37.500
 111 15054 65  NEVADA  D REID          12  373   0.968  37.500
 111 29906 62  COLORAD D UDALL         21  370   0.943  39.000
 111 40909 40  VIRGINI D WARNER        28  372   0.925  40.000
 111 40910 62  COLORAD D BENNET        18  363   0.950  42.000
 111 40703 14  PENNSYL D CASEY         14  373   0.962  42.000
 111 40900 81  ALASKA  D BEGICH        14  363   0.961  42.000
 111 15425 37  SOUTH D D JOHNSON       10  363   0.972  44.000
 111 40907 47  NORTH C D HAGAN         20  369   0.946  45.000
 111  1366 56  WEST VI D BYRD  ROBER   17  228   0.925  46.000
 111 40702 64  MONTANA D TESTER        13  371   0.965  48.000
 111 14203 64  MONTANA D BAUCUS        17  370   0.954  48.000
 111 49702 45  LOUISIA D LANDRIEU      18  350   0.949  48.000
 111 94910 14  PENNSYL D SPECTER        6  190   0.968  50.000
 111 40700 33  MINNESO D KLOBUCHAR     29  369   0.921  51.000
 111 40301 42  ARKANSA D PRYOR         14  372   0.962  52.500
 111 15502 36  NORTH D D CONRAD        25  360   0.931  52.500
 111 40706 40  VIRGINI D WEBB          41  372   0.890  54.000
 111 14812 36  NORTH D D DORGAN        16  367   0.956  55.000
 111 29305 42  ARKANSA D LINCOLN       21  371   0.943  56.000
 111 49309 25  WISCONS D FEINGOLD      67  373   0.820  57.000
 111 40701 34  MISSOUR D MCCASKILL     66  369   0.821  58.000
 111 49901 22  INDIANA D BAYH          61  370   0.835  59.000
 111 40103 35  NEBRASK D NELSON  BEN   46  373   0.877  60.000
 111 14661  2  MAINE   R SNOWE         23  373   0.938  61.000
 111 49703  2  MAINE   R COLLINS       19  373   0.949  62.000
 111 14910 14  PENNSYL R SPECTER       10  167   0.940  63.000
 111 49903 24  OHIO    R VOINOVICH     55  359   0.847  64.000
 111 14506 22  INDIANA R LUGAR         55  370   0.851  65.000
 111 40300 81  ALASKA  R MURKOWSKI     30  365   0.918  66.000
 111 15501 34  MISSOUR R BOND          38  356   0.893  67.000
 111 40304 54  TENNESS R ALEXANDER     27  368   0.927  68.000
 111 14826  4  NEW HAM R GREGG         49  332   0.852  69.000
 111 40501 43  FLORIDA R MARTINEZ      37  245   0.849  70.000
 111 14009 46  MISSISS R COCHRAN       30  367   0.918  71.000
 111 94659 41  ALABAMA R SHELBY        36  373   0.903  72.000
 111 49307 67  UTAH    R BENNETT       20  361   0.945  73.000
 111 14503 67  UTAH    R HATCH         37  366   0.899  74.000
 111 29534 46  MISSISS R WICKER        26  370   0.930  75.000
 111 14852 32  KANSAS  R ROBERTS       16  355   0.955  76.000
 111 49306 49  TEXAS   R HUTCHISON     27  349   0.923  77.000
 111 29523 32  KANSAS  R BROWNBACK     24  369   0.935  78.000
 111 14921 51  KENTUCK R MCCONNELL     23  372   0.938  79.000
 111 40902 63  IDAHO   R RISCH         16  372   0.957  80.500
 111 29345 63  IDAHO   R CRAPO         20  371   0.946  80.500
 111 40905 35  NEBRASK R JOHANNS       27  347   0.922  82.000
 111 29566 48  SOUTH C R GRAHAM        34  363   0.906  83.500
 111 14226 31  IOWA    R GRASSLEY      32  373   0.914  83.500
 111 40305 49  TEXAS   R CORNYN        19  364   0.948  85.000
 111 29918 45  LOUISIA R VITTER        26  365   0.929  86.000
 111 40911 43  FLORIDA R LEMIEUX        9  109   0.917  87.000
 111 29754 37  SOUTH D R THUNE         21  373   0.944  88.000
 111 49706 68  WYOMING R ENZI          20  367   0.946  90.000
 111 40705 54  TENNESS R CORKER        47  368   0.872  90.000
 111 40707 68  WYOMING R BARASSO       20  373   0.946  90.000
 111 15039 61  ARIZONA R MCCAIN        23  365   0.937  92.000
 111 29512 44  GEORGIA R CHAMBLISS     16  362   0.956  93.500
 111 29909 44  GEORGIA R ISAKSON       20  365   0.945  93.500
 111 29548 47  NORTH C R BURR          21  366   0.943  95.000
 111 29537 65  NEVADA  R ENSIGN        20  363   0.945  96.000
 111 49700 41  ALABAMA R SESSIONS      19  354   0.946  97.000
 111 15429 61  ARIZONA R KYL           22  369   0.940  98.000
 111 15424 53  OKLAHOM R INHOFE        16  360   0.956  99.000
 111 15406 51  KENTUCK R BUNNING       21  344   0.939 100.000
 111 29936 48  SOUTH C R DEMINT        12  370   0.968 101.000
 111 29555 53  OKLAHOM R COBURN         9  365   0.975 102.000