Why are Ocasio-Cortez, Omar, Pressley, and Talib estimated to be moderates by NOMINATE?

Jeff Lewis

January 20, 2022

In a previous post written last month, I explained why newly elected New York Congresswoman Alexandria Ocasio-Cortez is not estimated by NOMINATE to be among the most liberal members of the Democratic caucus. At that post, I focused on the votes that led NOMINATE to moderate her ideal point and, in particular, to locate Ocasio-Cortez at a much more moderate position that other progressive first termers such as Lauren Underwood, Rashida Tlaib, and Ilhan Omar. Since that time, new rollcalls taken on funding for the border crisis have pushed Tlaib, Omar, and Ayanna Pressley, who had previously been estimated to be among the most progressive Democrats, towards the location occupied by Ocasio-Cortez. Interestingly, Lauren Underwood's estimated position has not shifted and remains among the very most liberal Democratic first termers as estimated by NOMINATE.

The logic driving these new placements exactly follows that described in the previous post and I refer the reader to that post for a more detailed explanation. Here I will simply highlight those new votes on which Ocasio-Cortez, Omar, Tlaib, and Pressley broke ranks with nearly every other member of Democratic caucus and voted with nearly every Republican. Those votes are interpreted by NOMINATE as conservative votes and NOMINATE adjusts those members' locations to accommodate those votes accordingly. Over time, we expect those progressive members' ideal points to drift back towards the left flank of their party as more votes that cleave all of the progressives from the rest of Democratic conference and the Republican conference are taken.

Liberal rankings of freshman Democrats in the 116th House

Here we see the first-dimension NOMINATE score ranking of freshman Democrats from most to least liberal as of January 20, 2022. Note that Underwood remains among the most liberal of the new class, but Omar, Pressley, and Tlaib are longer estimated to be among the most progressive as they were in the previous post.

Rank Member NOMINATE 1st Dimension
1 GARCIA, Sylvia (TX-29) -0.817
2 CASTEN, Sean (IL-6) -0.565
3 UNDERWOOD, Lauren (IL-14) -0.544
4 LEVIN, Andy (MI-9) -0.518
5 GARCÍA, Jesús (IL-4) -0.484
6 DEAN, Madeleine (PA-4) -0.478
7 TRAHAN, Lori (MA-3) -0.462
8 ALLRED, Colin (TX-32) -0.430
9 ESCOBAR, Veronica (TX-16) -0.419
10 NEGUSE, Joseph (CO-2) -0.418
11 FLETCHER, Elizabeth (TX-7) -0.408
12 WEXTON, Jennifer (VA-10) -0.385
13 HARDER, Josh (CA-10) -0.378
14 CISNEROS, Gil (CA-39) -0.376
15 LEVIN, Mike (CA-49) -0.374
16 HAYES, Jahana (CT-5) -0.367
17 SHALALA, Donna (FL-27) -0.352
18 MUCARSEL-POWELL, Debbie (FL-26) -0.345
19 SCHRIER, Kim (WA-8) -0.344
20 COX, TJ (CA-21) -0.343
21 ROUDA, Harley (CA-48) -0.336
22 HAALAND, Debra (NM-1) -0.332
23 STEVENS, Haley (MI-11) -0.331
24 STANTON, Greg (AZ-9) -0.321
25 SLOTKIN, Elissa (MI-8) -0.319
26 HOULAHAN, Christina (PA-6) -0.316
27 CRAIG, Angela (MN-2) -0.312
28 PRESSLEY, Ayanna (MA-7) -0.311
29 HILL, Katie (CA-25) -0.306
30 LEE, Susie (NV-3) -0.292
31 OMAR, Ilhan (MN-5) -0.288
32 PAPPAS, Chris (NH-1) -0.287
33 KIM, Andy (NJ-3) -0.286
34 CROW, Jason (CO-6) -0.280
35 TRONE, David (MD-6) -0.274
36 McBATH, Lucy (GA-6) -0.266
37 MALINOWSKI, Tomaz (NJ-7) -0.262
38 PHILLIPS, Dean (MN-3) -0.259
39 TLAIB, Rashida (MI-13) -0.256
40 DAVIDS, Sharice (KS-3) -0.254
41 OCASIO-CORTEZ, Alexandria (NY-14) -0.245
42 AXNE, Cynthia (IA-3) -0.242
43 DELGADO, Antonio (NY-19) -0.232
44 FINKENAUER, Abby (IA-1) -0.224
45 SHERRILL, Mikie (NJ-11) -0.199
46 LURIA, Elaine (VA-2) -0.196
47 PORTER, Katie (CA-45) -0.184
48 ROSE, Max (NY-11) -0.176
49 SPANBERGER, Abigail (VA-7) -0.174
50 HORN, Kendra (OK-5) -0.169
51 TORRES SMALL, Xochitl (NM-2) -0.163
52 BRINDISI, Anthony (NY-22) -0.154
53 VAN DREW, Jefferson (NJ-2) -0.147
54 CUNNINGHAM, Joe (SC-1) -0.131
55 GOLDEN, Jared (ME-2) -0.112
56 McADAMS, Ben (UT-4) -0.069
57 HALL, Kwanza (GA-5) NA
58 SAN NICOLAS, Michael (GU-1) NA
59 PLASKETT, Stacey E. (VI-1) NA

Votes that moderate Ocasio-Cortez, Omar, Pressley and Tlaib's NOMINATE placements

The table below shows all of the votes on which Ocasio-Cortez, Omar, Pressley and Tlaib are predicted by NOMINATE to have less than a 40 percent chance (on average) of casting a vote on the side that they did and on which they all voted the same way. The table also shows the predicted probability of votes cast by Underwood on those same rollcalls (recall that Underwood is estimated to be second most liberal Democratic freshman). The roll call numbers shown in the first column are also clickable links to the pages for those votes on Voteview. The votes are sorted by the average probability that NOMINATE attaches to their votes on each roll call. The most important of these votes for determining member's locations is Roll Call 413 for which Ocasio-Cortez, Omar, Tlaib and Pressley were the only Democrats to defect from their Democrat colleagues and vote with all but three of members of the Republican caucus.

Underwood
Ocasio-Cortez/Omar/Pressley/Tlaib
Rollcall Bill Description Vote Prob. Votes Avg. Prob.
949 HR133 United States-Mexico Economic Partnership Act (On Concurring in Senate Amdt with Portion of Amdt Comprising of Divisions B, C, E, and F) Y 87.4 NNNN 34.1
851 HR6395 William M. (Mac) Thornberry National Defense Authorization Act (On Passage) Y 89.4 NNNN 38.2
937 HR6395 William M. (Mac) Thornberry National Defense Authorization Act (On Agreeing to the Conference Report) Y 91.1 NNNN 35.3
450 HR2500 On Agreeing to the Amendment Y 91.2 NNNN 22.9
72 HR840 On Agreeing to the Amendment Y 96.8 NNNN 18.3
86 HJRES31 Making further continuing appropriations for the Department of Homeland Security for fiscal year 2019, and for other purposes (On Agreeing to the Conference Report) Y 96.8 NNNN 20.5
346 HR2740 On Agreeing to the Amendment Y 98.5 NNNN 27.5
905 HR4447 Expanding Access to Sustainable Energy Act (On Passage) Y 99.6 NNNN 38.9
630 HR3055 Making appropriations for the Departments of Commerce and Justice, Science, and Related Agencies for the fiscal year ending September 30, 2020, and for other purposes (On Motion to Concur in the Senate Amendment with an Amendment) Y 99.7 NNNN 24.1
413 HR3401 Making emergency supplemental appropriations for the fiscal year ending September 30, 2019, and for other purposes (On Passage) Y 100.0 NNNN 24.3
651 HRES326 Expressing the sense of the House of Representatives regarding United States efforts to resolve the Israeli-Palestinian conflict through a negotiated two-state solution (On Agreeing to the Resolution) Y 100.0 NNNN 9.5
805 HRES967 Providing for consideration of H. Res. 965; providing for consideration of the bill (H.R. 6800) making emergency supplemental appropriations for the fiscal year ending September 30, 2020, and for other purposes; providing for proceedings during the period from May 19, 2020, through July 21, 2020; and for other purposes (On Agreeing to the Resolution) Y 100.0 NNNN 39.4
877 HR7617 Making appropriations for the Department of Defense for the fiscal year ending September 30, 2021, and for other purposes (On Passage) Y 100.0 NNNN 37.6

To maximize the likelihood of these votes under NOMINATE's spatial voting model, Ocasio-Cortez, Omar, Pressley, and Tlaib's positions are shifted away from Underwood's location and towards the locations of the Republican members. As described in the previous post, shifting their locations in this way does not substantially reduce the fit of the very large number of votes on which Ocasio-Cortez, Omar, Pressley and Tlaib sided with Underwood, but not moving them would greatly reduce the fit model for those few rollcalls on which they did not (such as Roll Call 413).