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 politics.

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 how politics plays out across the city. The database is designed to be easy to use, but here are some instructions to guide you. Note that because it helps to simultaneously see all the controls and the map, the tool works better on big screens, so it might be a good idea to work on a laptop or tablet rather than your phone. The next paragraphs and bullet points can help you explore the database.

In the “Search race or candidate” box at the top left, begin by typing in the name of a candidate, office type, election type, or year of election.

  • The database will suggest 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.”
  • If you are not quite sure what candidate or election you are looking for, you can click on “Search Tools” just below the search box for some common types of elections and offices.

A list of the elections that best fit your search will appear below the Search box. There are two ways to select race results within each race.

  • First, you can click on the blue-lettered name of the office/year. This will display a map showing which candidate came in first in each part of the city, with a different color representing each candidate that took part in the race. The key for these colors is in the lower right corner (Note that for some races, like ballot measures and judicial retention, the “candidates” may be “Yes” and “No.”
  • Second, you can map a particular candidate’s results by area to see where they got a greater or lesser percent of the vote. Click on the small person-shaped icon where it says “Candidate Maps” to pull down a menu of all the candidates in the race. Choose the candidate whose results you’d like to see displayed. The percentages associated with the colors used to display areas of relative electoral strength and weakness are shown in a box at the lower right. These percentages will change for each candidate, so pay attention to the numbers there. [Note also that for some votes, like ballot measures or judges, “Yes” or “No” are the candidates.]

When you choose a map, the results from that election will be projected on the map of Chicago. There are a few map options you can choose to understand and visualize the results.

  • In general, to move around the map, and zoom in, you can use the same kinds of controls you would use on any web-based or Google-style map.
  • Just above the map, there is a pull-down menu that allows you to change between maps associated with the chosen race. “Aggregate” refers to the winner-by-area map, and the other options are for the candidates in the race.
  • To the right of the pull-down menu are options to view the results at the Ward or Precinct level. There are 50 Wards, and just over 2000 Precincts, in the city. 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 interesting.
  • 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. A small bubble pops up to give vote totals and percentages by candidate in that area.
  • In the top-left corner of the map, there is a small address search box. You can type in any address in Chicago and the map will take you to that area, and automatically give you the results from that area (again, Ward or Precinct depending on which option you’ve chosen). 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).
  • Above the map, there is a description of which results you are currently viewing. Note that this description is also present in the URL for the map, so you can quickly copy and paste the URL itself to share the map with others or place a link to the database in text elsewhere.
  • Just to the right of the map description are two buttons that allow you to view the results as a map (as we have been doing) or as a graph. Clicking on “Graph” will bring up a bar chart showing the overall results of the race you’re analyzing.

A Handy Example

Suppose you wanted to see how well Mayor Rahm Emanuel did in different parts of the city in the most recent mayoral election, the municipal run-off in April of 2015 in which he competed as the incumbent against challenger County Supervisor Jesus “Chuy” Garcia. This example will walk you through such a search, noting other aspects that can help you use the database as well. It’s basically a concrete example of the tips above.

  1. Type in “Emanuel” in the Search box. Even before you finish typing, “Rahm Emanuel” should appear in the choices that pop up below. Note that other choices with similar names also appear. This is helpful in case you can’t quite remember a candidate’s name. Alternatively, you can start by typing “Mayor” and find the election that way.
  2. Scroll down to the box that says “Rahm Emanuel” and click on his name. A list of elections appears below the Search box. These include races when Emanuel ran for Congress before becoming Mayor, as well as races run by Manny Flores in 2007 because of name similarity. Scroll down to find the results that say “Mayor.” Notice that there is more than one Mayor race from 2015–there’s the February first round, and then the Municipal Run-off in April.
  3. Click on the blue-lettered header for the Run-off. Automatically, different colors appears on the map at right. Those represent the places in the city where Emanuel or Garcia received more votes, with a color assigned to each of them. Emanuel came in first in most areas of the city, while Garcia had a stronger base on the Northwest and Southwest sides (as well as wards in Rogers Park and the Far Southeast side).
  4. In the pull-down menu at top left, you can choose to map a particular candidate’s results. Click to pull down the menu and choose “Rahm Emanuel.” Now a choropleth (a map in which different colors represent different values/categories of a variable measure) of the percent of ballots cast for Emanuel is displayed by ward. The key is in the lower righthand corner. In the lightest-colored wards, he received between 20 and 25% of the vote. In the darkest-colored wards, he received between 83 and 85% of the vote.  Notice that any time you change candidates or levels of analysis, the color scale also shifts a little (the categories are based on the distribution of support for that candidate in that election, and are calculated using standard deviations from the mean).
  5. Click on the darkest-color ward near downtown, just to the left of the “GO” in Chicago. A bubble with the results for that ward pops up, telling us that Emanuel did quite well in this downtown ward, winning the vote total 11,504-2041, or 85% to 15%. If you click on the lightest-color box just east of where the map says “Cicero” to the left, you can see that the results in that Southwest Side ward were basically the opposite. Now click on “Precinct” above the map to change to the smaller, precinct view. Note that the color scale changed: it’s now more extreme because the distribution of outcomes for 2,000+ Precincts is different than it is for 50 Wards. Precincts are small, so it’s a little hard to say much about the whole city, but they’re better for analyzing very-local results.
  6. In the address search box, type in “1060 W Addison,” former home of noted traffic menace Elwood BluesA bubble pops up displaying the local results in the the 44th Ward, 31st Precinct. Mr. Blues and his neighbors tended to support Emanuel.  The same was basically true in most surrounding precincts.
  7. Click on “Graph” at the very top of the map window. A bar graph appears showing the overall results of the race, city-wide. Emanuel won 56% of the vote, Garcia 44%. Click back to “Map” and the “Aggregate” results map reappears.
  8. Finally, copy the URL of the map in your browser’s address bar. You can mail it to a friend to show them the results you’ve analyzed…and to introduce them to the CDP’s Elections Database.

That’s it! You can search other races to compare the patterns over time, space, or office–what’s the same, what’s different. And you can take a screenshot of the results you map and use them as part of another analysis you’re working on.

In the coming months, we’ll be adding new features and data to the tool, so bookmark the page and check back in!