| To estimate the 2020 population of Idaho and its distribution, I took the April 2000 population of each county. I then recorded its growth up to July 2009 (as the 2010 numbers aren't yet out) and extrapolated this out to April 2020.
I only split two counties, namely Ada and Canyon, but here I encountered some problems. The city of Boise itself has enjoyed only modest growth, whereas other cities have nearly doubled in size in the past decade. It's unlikely this will be allowed to continue unimpeded for another decade, but by the same token other smaller cities will be likely to experience explosive growth.
Rather than trying to model this, I took the cop-out option of working out what proportion of the two counties I needed to draw into other districts to achieve population equality, then removing them based on the population in Dave's Redistricting App. This is not a rigorous method and will undoubtedly be out by several thousand in the final analysis, but it did at least allow a rough picture of the likely districts to be drawn.
ID-1
2000 population: 466396
Estimated current population: 524907
Estimated 2020 population: 614623
This district combines the Idaho panhandle with most of the Treasure Valley and a couple of rural counties thrown in for population equality.
It's slightly oversized because it made the mental arithmetic slightly easier, but moving one block group would fix that and there are plenty of suitable ones around Boise.
Guaranteed safe Republican.
ID-2
2000 population: 360291
Estimated current population: 486060
Estimated 2020 population: 610485
From Boise in north-central Ada County this heads west along I-84 (west) until Caldwell, taking in Meridian and Nampa along the way. For the most part the Boise River is the northern boundary, but it heads beyond that to take in northern parts of the capital as well as the town of Eagle.
As the scale shows, it's probably only around 200 square miles and hence takes up less than a quarter of a percent of the state's land area.
Probably leans Republican, but a lot less so than the other two districts.
ID-3
2000 population: 467289
Estimated current population: 534835
Estimated 2020 population: 613230
This district fits communities of interest surprisingly well, as it takes in all of eastern Idaho and the Magic Valley as well as the Wood River Valley.
It would also include the rest of central Idaho, but I had to remove Custer and Lemhi counties to ID-1 for population reasons. This is a shame, as they have no road connections in that direction. However, if, as seems likely, population in rural eastern counties continues to decline, it might be possible to include them in this district in a 2020 map.
Would be monolithically Republican, even if it wasn't even more Mormon than the present ID-2 already is. |