Analyzing Colorado’s Adjusted Redistricting Data

Overview

Colorado uses adjusted (or modified) data for state legislative and state congressional redistricting.

• 5,773,714 total population in the original PL file
• 5,773,714 total population in the adjusted PL file
• 0 total population difference between the two

Even in states where where the total population is unchanged, the distribution of population within the state can be affected.

To give you a sense for how these population shifts affect Colorado’s redistricting, the average district sizes in Colorado are:

• 88,826 people per state House district
• 164,963 people per state Senate district

The dataset used to create this report is the official redistricting dataset.

County Level Analysis

See the appendix for a detailed breakdown of county level population changes.

Block Level Analysis

In general, the changes in block population are not uniform: most blocks are unaffected by modification, while a handful of blocks lose a large amount of population that goes to a larger number of blocks in smaller quantities.

• 140,345 census blocks in Colorado
• 130,365 census blocks have the same population following modification
• 9,958 census blocks gained population following modification
• 22 census blocks lost population following modification (Of the 22 census blocks that lost population following reallocation, 22 contained facilities according to our analysis conducted with PPI data.)
• 3 census blocks have a negative population following modification.

Official Language

The official language for Colorado’s adjustment is:

For purposes of the census, the federal census bureau counts prisoners in the correctional facility in which they were housed as of April 1 of the year in which the census was taken. For redistricting purposes, the act reassigns those persons to their last known residence in Colorado prior to incarceration. If the last known residence is outside of Colorado or the last known residence is unknown, the prisoners are counted for purposes of redistricting at the correctional facility. [S]