New population estimates point to a third congressional seat for fast-growing Idaho

It’s looking more and more likely that Idaho is going to get that long-coveted third congressional seat after the 2030 Census.

Based on new Census population estimates and an analysis by the Brennan Center for Justice, Idaho stands to gain one seat in the U.S. House of Representatives.

According to the Census estimates for 2023 population, Idaho was the fourth-fastest growing state, percentage-wise, behind South Carolina, Florida and Texas.

Idaho gained 25,730 people in 2023, a 1.3% increase from the previous year.

According to the Brennan Center analysis of the new Census numbers, the overall trend for the decade portends a dramatic political shift in congressional seats, with Southern and Mountain West states gaining seats at the expense of states such as California, New York, Illinois and Pennsylvania.

If trends continue, California could lose four seats, New York three, Illinois three and Pennsylvania two, while Texas could gain four, Florida three and Tennessee, North Carolina, South Carolina and Georgia one, according to the Brennan Center.

The prospect of a third House seat offers an interesting opportunity for Idaho’s bipartisan Commission for Reapportionment, which is tasked every 10 years with divvying up the state’s population into not only state legislative districts but also congressional districts.

Drawing state legislative districts is tricky and involves a number of considerations. Drawing congressional districts, especially in Idaho where there are only two, is much more straightforward: Just divide the state into two parts with equal populations.

In Idaho, that has meant simply moving the north-to-south dividing line farther and farther west to balance out the population numbers between Districts 1 (western Idaho) and 2 (eastern Idaho). Currently, the dividing line is somewhere around Eagle Road.

But with three districts, the possibilities grow more interesting.

Is it possible that Idaho could actually need to be concerned about gerrymandering?

It’s possible, but Idaho is lucky to have a truly bipartisan redistricting commission.

Idaho’s redistricting commission is composed of six members: three Republicans and three Democrats.

Idaho is one of 14 states with an independent commission that makes the redistricting decision. Partisanship varies from state to state, with appointees coming from various political offices, but Idaho is one of the few states with a bipartisan, even-numbered independent commission, meaning no one party has an advantage.

Idaho voters in 1994 approved a constitutional amendment creating our redistricting commission whose six members are individually appointed by the House speaker, Senate president pro tem, the House and Senate minority leaders, and the chairs of the state Republican and Democratic parties.

Even though it’s a system that works, and voters approved a constitutional amendment to enshrine it, I wouldn’t be surprised if Republican legislators try to mess with the system so that they have an advantage leading up to the 2030 Census.

With three districts, it would seem pretty straightforward to divide the state into three natural districts: Southwest Idaho, North Idaho and East Idaho.

But it could be trickier than that.

Currently, Ada and Canyon counties combined account for 40% of Idaho’s population. That percentage likely will grow even more over the next seven years.

Ada County, alone, has a higher population (525,000) than the 10 counties considered North Idaho combined (377,000).

So no matter what, the Treasure Valley would need to get split up.

But how?

Republicans likely would be champing at the bit to split up the Democratic voters of the city of Boise. A Democratic U.S. representative is still highly unlikely, no matter how you slice it, especially knowing that an overwhelming majority of the new residents moving into Idaho are registering as Republicans, and that trend is likely to continue to 2030. But with a congressional district that includes all of Boise, perhaps any Republican running in that district would need to be more moderate.

Regardless, adding a third congressional district to Idaho offers a slew of interesting possibilities.

Keep your eyes open for attempts to game the system — because the prize is unusually large this time around.