Section 1: Getting started
Section 2: Accessing Census data
Section 3: Calculating the impact on districts
Section 4: Repairing your democracy, now and in the future
Correctional Facility Locator (2020)
Correctional Facility Locator (2010)
Correctional Facility Locator (2000)
Vote dilution calculator
2020 Worksheet [DOC] a single worksheet updated for use after the 2020 Census to determine if a county included or excluded the incarcerated population.
Worksheets [DOC] with all of the tables used in this toolkit
Handling lettered blocks
Determining whether prisoners were included or excluded from districts with known populations.
District population deviations & split prisons
Weighted Voting

Section 3.
Calculating the impact on individual districts

In this section, you will figure out which districts contain the Census blocks with prisoners. This will help you determine how many actual constituents and how many "phantom" constituents (prisoners) there are in each district. You will then be able to compare each district's deserved political representation with its actual representation; in other words, you will be able to calculate exactly how your local democracy has been skewed.

Step 1. Determine which prison blocks are in which district.

In the previous section, you developed a list of Census blocks that contain state or federal prison populations. Now we will connect this information to your county legislative district lines. Unfortunately, there is no national repository for county legislative district boundaries, so you will need to get this information from your county legislature. You do not necessarily need a map; a description of the districts often works.

If for some reason your county legislature is uncooperative, the information may also be found in the following places:

  • The web pages of individual legislators or their campaigns
  • The state GIS clearinghouse. GIS stands for Geographic Information System. A handful of states collect their county district maps and make them available in GIS formats, or on the internet.
  • County newspapers. County newspapers often publish the maps when new district boundaries are adopted, typically 2-3 years after the decennial Census.

If any of the state or federal prison blocks in your county were mentioned in the Count Question Resolution program, you may have to go through some extra steps. You should determine whether the corrected location is in the same legislative district as the incorrect district. If so, it will not matter whether the legislature used the Count Question Resolution results to draw districts. But if the correction moved the prison to a different part of the county, then you will need to ask the legislature whether the county corrected any of the PL94-171 redistricting data when drawing the districts.

Step 2. Calculate the ideal district size

Districts are drawn so that each contains close to the same number of residents as other districts. Some county legislatures make district population information readily available, but others do not. If you know the Census population for each district, enter the actual Census populations in the second column of the table below and read District population deviations & split prisons in the Appendix.

Warning: Do not use current Census estimates of your county population. You need Census 2000 data. If this isn't available, look up your county in the data search tool of our Too big to ignore: How counting people in prisons distorted Census 2000 report.

If you have single-member districts and the population data is unavailable, you can instead use the ideal district size for each district. This is calculated by taking the county's census population and dividing it by the number of districts.

If you have multimember districts, see Section 1, Step 4 and use the district population data from that table for your district sizes.

If you have a weighted voting system, use the total Census population of each district as the ideal district size. Because this type of districting can appear counter-intuitive, you should not find it difficult to get the district population for each district. This information should be readily available from county officials.

District Number The total population of each district. (Use the ideal population size if that is all that is available.) Number of state and federal prisoners Percentage of district that is people in state or federal prison

Step 3. Calculate how many state or federal prisoners are in each legislative district:

In Step 1, you identified which census blocks containing state or federal prisoners were in each legislative district. Add up the totals for each district and place that figure in the third column of the table.

Step 4. Calculate the percentage of each district that is not local residents, but instead people in state or federal prison.

To calculate how your votes are diluted by the presence of prisoners in other districts, you need to know what percentage of each county district is state or federal prisoners. For each row in the fourth column of the table above, divide the number of state or federal prisoners by the district population.

The district with the largest percentage is the district with the largest inflation of its voting power. By extension, every district without prisons has their votes diluted by the same percentage.

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