Why is Alexandria Ocasio-Cortez estimated to be a moderate by NOMINATE?

Jeff Lewis

January 20, 2022

Media coverage of newly elected New York Congresswoman Alexandria Ocasio-Cortez describes her as liberal or even "ultra-liberal" with good reason. For example, she supports the green new deal, reparations for slavery, and abolishing ICE --- all positions associated with the left wing of the Democratic caucus. Curiously, more than 150 roll calls into the 116th Congress, her first-dimension NOMINATE score places her to the right of the majority of freshman Democrats. So, why does NOMINATE think Ocasio-Cortez is a moderate? This question is made all the more puzzling because NOMINATE ranks Lauren Underwood, Rashida Tlaib, and Ilhan Omar as the three most liberal of the new Democrats in the House which is consistent with the media coverage and public statements of those three members. In what follows, I identify the roll calls that pull Ocasio-Cortez's NOMINATE location away from the locations of Underwood, Tlaib and Omar and explain why NOMINATE cannot, as yet, conclude that Ocasio-Cortez belongs among the left-wing members of the Democratic caucus.

As shown below, the reason is quite simple. Because there have been relatively few roll calls taken that divide the left wing of the Democratic caucus from the moderates, there have been few opportunities for freshman liberals to show their stripes. On the vast majority of votes, members located at Ocasio-Cortez's moderate position and, for example, Omar's liberal position are expected by NOMINATE to vote the same way. While there are votes on which Ocasio-Cortez joins other strong liberals in voting against the moderates in her party, there are a handful of votes on which Ocasio-Cortez has gone against nearly every other Democrat including Omar, Tlaib and Underwood and sided with (nearly) every Republican. While Congressional observers understand that votes like Ocasio-Cortez's vote against the rules of the House are protest votes, NOMINATE does not. Rather, NOMINATE sees these as instances in which Ocasio-Cortez looks like a conservative and it adjusts her location to be more conservative accordingly.

In those cases in which a large number of liberal members join the Republicans in voting against the Democratic moderates, NOMINATE concludes that the vote did not strongly divide liberals and conservatives. Consequently, NOMINATE discounts those sorts of votes in determining members' locations. However, when a member goes alone (or nearly so), in bucking her party, NOMINATE finds that to be highly informative about the member's location (this is how NOMINATE is able to correctly infer that Susan Collins is a moderate). This is what leads Ocasio-Cortez to be placed in the middle.

Over time, we expect that the 116th Congress will hold more votes that sharply divide the progressive wing of the Democratic party from the Democratic moderates and Republicans, but until it does, Ocasio-Cortez's willingness to protest alone will lead NOMINATE not to locate her among the Congress's most liberal members.

Liberal rankings of freshman Democrats in the 116th House

Here we see that while most of the highest-profile new liberals in the Congress are at the top of NOMINATE's ranking, Ocasio-Cortez is only estimated to be the 41st most liberal of the 56 new Democrats.

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
## Warning: One or more parsing issues, see `problems()` for details

Votes that moderate Ocasio-Cortez's NOMINATE placement

The table below shows all of the votes on which Ocasio-Cortez is predicted by NOMINATE to have less than a 40 percent chance of casting a vote on the side that she did. 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 probability that NOMINATE attaches to Ocasio-Cortez's vote on each roll call. These votes tell us just about all we need to know about why Ocasio-Cortez is estimated to be a moderate by NOMINATE.

For example, on rollcall number 48, Ocasio-Cortez was the only Democrat to vote "nay" and only ten Republicans voted "Yea." On that vote, liberal members such as Underwood, Tlaib, and Omar are predicted to vote "Yea" with near (certainty). Even at Ocasio-Cortez's moderate NOMINATE position, NOMINATE only gives her "Nay" vote a 1.8 percent chance. All of these votes illustrate instances in which Ocasio-Cortez broke from her party including at least some or all of its left-wing. In order to accommodate these maverick votes, NOMINATE adjusts her position to reflect that she has on several occasions cast votes that are (otherwise) strongly consistent with being a conservative.

Rollcall Bill Description Vote Prob. Votes Avg. Prob.
48 HR648 Consolidated Appropriations Act, 2019 (On Passage) N 0.7 YYY 99.6
45 HJRES28 Making further continuing appropriations for fiscal year 2019, and for other purposes (On Passage) N 1.6 YYY 99.2
50 HJRES31 Making further continuing appropriations for the Department of Homeland Security for fiscal year 2019, and for other purposes (On Passage) N 2.0 YYY 99.0
699 HR5377 Restoring Tax Fairness for States and Localities Act (On Passage) N 5.4 YYY 96.0
340 HR2740 On Agreeing to the Amendment N 5.9 NYY 38.5
228 NA On Approving the Journal N 6.0 YYY 85.6
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) N 11.1 NNY 21.1
623 HR4863 United States Export Finance Agency Act (On Passage) N 15.4 ANY 50.5
795 HRES891 Providing for consideration of S.J. Res. 68, to direct the removal of US Armed Forces from hostilities against the Islamic Republic of Iran; the Senate amendment to H.R. 2486, the FUTURE Act; and H.R. 6172, the USA FREEDOM Reauthorization Act of 2020; and for other purposes (On Agreeing to the Resolution) N 15.8 YYY 93.5
6 HRES6 Adopting the Rules of the House of Representatives for the One Hundred Sixteenth Congress, and for other purposes (On Agreeing to Title I of the Resolution) N 16.3 YYY 90.3
688 HR1865 National Law Enforcement Museum Commemorative Coin Act (On Motion to Concur in the Senate Amendment with an Amendment) N 16.7 NYY 50.7
57 HR769 Counterterrorism Advisory Board Act (On Motion to Suspend the Rules and Pass) N 17.3 NNY 30.9
72 HR840 On Agreeing to the Amendment N 18.2 NNY 31.8
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) N 20.9 NNY 34.4
450 HR2500 On Agreeing to the Amendment N 23.7 NNY 36.4
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) N 26.2 NNY 38.9
413 HR3401 Making emergency supplemental appropriations for the fiscal year ending September 30, 2019, and for other purposes (On Passage) N 28.4 NNY 39.4
346 HR2740 On Agreeing to the Amendment N 29.3 NNY 42.3
56 HR449 Pathways to Improving Homeland Security at the Local Level Act (On Motion to Suspend the Rules and Pass) N 30.9 YYY 80.0
668 HRES758 Providing for consideration of H.R. 3, the Elijah E. Cummings Lower Drug Costs Now Act; H.R. 5038, the Farm Workforce Modernization Act of 2019; the conference report to accompany S. 1790, the National Defense Authorization Act (On Agreeing to the Resolution) N 33.7 YYY 78.9
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) N 34.4 NNY 46.7
937 HR6395 William M. (Mac) Thornberry National Defense Authorization Act (On Agreeing to the Conference Report) N 35.8 NNY 48.5
269 HR2740 On Agreeing to the Amendment N 36.6 NYY 59.5
851 HR6395 William M. (Mac) Thornberry National Defense Authorization Act (On Passage) N 39.0 NNY 50.8

Few votes in the 116th House have divided liberal from moderate Democrats (through May 2019)

The following plot shows the probability that NOMINATE assigns to votes cast by Ocasio-Cortez against the average probability that it assigns to votes cast by Omar, Tlaib and Underwood on each rollcall in which Ocasio-Cortez, Omar, Tlaib, and Underwood all voted the same way. Here we see that on most of these votes, even with her moderate location, Ocasio-Cortez's votes are well predicted by NOMINATE. Put another way, we find only a small number of votes for which moving Ocasio-Cortez to a similar location to Omar, Tlaib and Underwood would substantially increase the fit of Ocasio-Cortez's votes. Thus, while her go-it-alone protest votes provide a strong impetus for NOMINATE to moderate Ocasio-Cortez's location, the large number of votes on which she agrees with the other liberal Democrats provide little impetus for moving her position leftward.

Likelihood of Ocasio-Cortez's votes by DW-NOMINATE position

## `summarise()` has grouped output by 'x1'. You can override using the `.groups` argument.

Here we plot the likelihood (represented as the geometric mean probability of her vote choices) of Ocasio-Cortez's votes being cast by a member located anywhere in the DW-NOMINATE space. Her actual estimated location, the one that maximizes the likelihood of her votes, is represented by the black dot. Note that the likelihood of her votes falls off rapidly as her location is shifted to the right while she can be moved along the edge of the space to the left with relatively less reduction in fit.