Population change in Vermont and implications for legislative reapportionment.
At 1 p.m. EDT today the U.S. Census Bureau released 2020 population counts for states to use in their state legislative redistricting process. The data are available for a range of geography - from state, all the way down to individual Census blocks and include counts by race, ethnicity, and select housing characteristics.
This first release of data has been made available in what the Census refers to as ‘legacy format summary files.’ VCGI has processed a few of the files and made data available as csv and shp files for Vermont at the following geographies: 1) Municipal, 2) House Districts and 3) Senate Districts. Refer to this documentation from the Census for a description of field names and other information.
We’ve also created several maps, charts, and tables that highlight population change in Vermont municipalities and implications for legislative reapportionment.
Population change in VT municipalities
Population change across Vermont cities and towns ranged from an increase of 2,507 people in Essex, and a decrease of 688 in Rutland City. The graphics below show population change from 2010 to 2020.
Thanks to work done by the Vermont Historical Society we also have data available for municipal population counts going back to 1791.
Legislative Reapportionment
Every ten years, following the decennial Census, states legislative districts are required to be redrawn allocated to ensure that the populations of each district have relatively equal representation in both chambers of the State House.
Learn more about the redistricting process on the Secretary of State’s website and this helpful presentation from Legislative Council to the Legislative Apportionment Board.
The graphics below highlight percentage deviation from ideal district populations for existing House and Senate districts in Vermont. There are several definitions that are helpful to understand when looking at these:
- Ideal District Population = State population (643,077) / # of members in chamber (150 for the House & 30 for the Senate) x # of members in district (either 1 or 2 for the house & between 1 and 6 for the Senate.) The ideal district population is 4,287 per House Representative and 21,436 per Senator.
- District Deviation = Actual district population – Ideal district population.
- Percentage Deviation = District Deviation / Ideal population x 100.
Generally speaking if a district has a percentage deviation greater than 10% over or under ideal, legal precedent would suggest that the district would likely exceed what is constitutionally acceptable.
Senate Districts
Of the 104 House districts, the ‘percent deviation from ideal’ for 21 districts are either over/under 10%. The graph below shows the distribution of percent deviation from ideal for all the House districts.