Database How-To

Welcome to the Chicago Elections Database how-to page. We are glad you are here to use our online tool for analyzing Chicago elections.


In the early 2000s, Jaime Dominguez led an innovative project to make Chicago political data more easily accessible. That was the Chicago Democracy Project’s first incarnation, and it is still available online here: A decade later, we’re reinvigorating that mission by launching an update that includes data from the intervening years, a new format for interacting with the data, and a blog that will bring together research and the people who can use it to better understand the local scene and affect evidence-based positive change in our communities.

Currently, our Chicago Elections Database has all the results from Chicago elections from 2005 to the present. We’ll be adding more features (including Census demographic measures and policy outcomes) over time. For now, this tutorial can help you get acquainted with using the database.

How to use the database

This is a web-based database that is useful in instantly displaying electoral results from the last decade of Chicago elections on a map of the city, so users can visualize and intuitively grasp some of the political relationships that play out across the city. The database is designed to be easy to use, there are three quick steps.

  1. In the “Search” box at the top left, begin by typing in the name of a candidate, office type, election type, or year of election. The software works by finding keywords automatically as you type them. As you type, a list of suggestions should appear below the Search box. If the term you are looking for appears, click on it, or highlight it and press “Return.”
  2. A list of the elections that best fit your search will appear below the Search box. Click on the election from which you want to see the results.
  3. The results from that election will be projected on the map of Chicago on the righthand side of the screen. In the upper left-hand corner of the map, you are given two kinds of options to tell you what results you want to see.
    1. First, choose the candidate from that race whose results you’d like to map out. We map the candidates one at a time, so you can see what percent each candidate got in each part of the city.
    2. Second, choose whether you’d like to see the results mapped at the Ward or Precinct level. There are 50 Wards, and just over 2000 Precincts. Usually the ward is the best way to see how the election played out across the city, but if you’re looking at a particular PART of the city, or within a particular ward, sometimes the precincts are more useful.
  4. That’s it! You’ve mapped the results from an election. We have three nice features right now that can help you learn more and interpret these results.
    1. First, you can click on any area (Ward or Precinct, depending on how you mapped it) to see a quick list of how each candidate did in that area.
    2. Second, you can type in any address and the map will take you to that area, and automatically give you the results from that area (again, Ward or Precinct). This is handy to learn what ward and precinct you are in, and to learn more about the very local results there (for city council, for example).
    3. Third, our database automatically calculates different values that will count as “high” or “low” support for each candidate in each race. The legend at the lower righthand corner of the map tells you what each color means, with more intense colors indicating higher levels of support. IMPORTANT NOTE: because the scale is different for each candidate, be careful comparing values across candidates.

Example: We want to see how well Mayor Rahm Emanuel did in different parts of the city in the most recent city election, the municipal run-off in April of 2015.

  1. Type in “Emanuel” in the Search box. Even before you finish typing, “Rahm Emanuel” should appear in the choices that pop up below. Click on his name.
  2. A list of elections appears below the Search box. These include some of the times Emanuel ran for Congress before becoming Mayor. Scroll down to find the results that say “Mayor.” Notice that there are more than one Mayor races from 2015–there’s the February first round, and then the Municipal Run-off in April. Click on that one.
  3. Automatically, a different colors appears on the map at right. In the pull-down menu at top left, you can choose to map a particular candidate’s results (in this case, Emanuel’s appeared automatically because he came in first in the election overall.
  4. You can choose a different candidate, or click the radio button to see precinct-level results. Notice that any time you change candidates or levels of analysis, the color scale also shifts a little (the categories are based on the average support for that candidate in that election).
  5. When you look at the precinct-level results especially, it’s useful to zoom in on a particular part of the map to see it clearly. Enter an address in the address search box on the map to have the page automatically zoom to the place you’re searching. It will tell you the local results in that election, as well as the Ward/precinct of the address you’ve searched for.
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Thomas Ogorzalek is co-Director of the Chicago Democracy Projeect, and Assistant Professor of Political Science and Urban Studies at Northwestern.