Realtime NOMINATE Ideology and Related Data

This section contains .csv files that provide descriptive data as well as ideological data for congressional rollcalls, individual member votes, members of congress, and parties. You can find information such the descriptions of rollcalls, what proportion of voting members were correctly classified by the ideological cutting line for that rollcall, the ideological position of members of congress, and more.

Both the rollcall data and the data on members are split into chambers and congresses, although you can select some combinations of the two to download. The data on parties is a dataset with some metadata about all of the different parties as well as their average ideological position and membership size broken down by congress and chamber.

You can see the about page for more information about NOMINATE.

Please cite the dataset as:
Lewis, Jeffrey B., Keith Poole, Howard Rosenthal, Adam Boche, Aaron Rudkin, and Luke Sonnet (2017). Voteview: Congressional Roll-Call Votes Database.
For information on the data files, please see the CSV data files documentation.

Information about congressional rollcalls

Information about votes members cast

Information about members of congress

Information about political parties

Extra Legacy Information

Clausen, Peltzman, and Issue codes for 1st to 113th Congresses

Ancillary Data and Analyses

We are pleased to present a collection of articles discussing data and analyses that make use of NOMINATE /, along with the source code used to produce the analyses. We hope these will be of use to scholars, journalists, and students interested in producing analysis using our data:

Polarization in Congress: Provides updated versions the classic Voteview plots of party mean DW-NOMINATE scores of overtime. Figures and the underlying data are available for download.

Presidential Support Scores: Presents member- and chamber-level presidential support score data. Shows how scores are calculated. Provides download links, summary plots, and a comparison to previously published scores.

Complete Database

Complete database (approx. 500MB zipped).
Our database is available in MongoDB bson/json format. This release is updated weekly. For information about specific data fields in the database, see the members data dictionary and rollcalls data dictionary.

Browse prior database releases
We retain a year worth of archival data online. Archival releases may be missing new rollcall or member data, and may also be missing corrections made to existing data.