According to population trends, four western states should gain one or two seats in Congress, while most of the losses will come from the rust belt.
Election Data Services used the Census Bureau population estimates to project which states would gain seats and which will see their congressional delegations get smaller. The big winners would be Texas, Florida, and Montana. Florida is on track to gain two seats, while Texas and Montana could gain two as well.
In the west, Arizona, Colorado Montana and Oregon are projected to gain seats.
Even though Utah’s population is growing at the third-fastest rate in the nation based on percentage, the population projections say the Beehive State is nowhere near gaining another seat in 2020. The number of seats in the House of Representatives is capped at 435. The table below shows which states are close to the cutoff line to gain a seat.
Daily Kos notes that the states projected to lose seats are mostly in the rust belt and Northeast, while the growth is in the Sun Belt
Interestingly, the largely Midwestern and Northeastern states that are projected to lose seats almost all trended Republican in 2016, while the mostly Sun Belt states forecast to gain seats almost all trended Democratic. These trends could benefit Democrats in the long term if they can start winning regularly in places like Arizona, Florida, and North Carolina, even if Republicans shift toward a greater reliance on the Rust Belt.
The 2020 reapportionment will also change how many Electoral College votes each state has. Based on these projections, Donald Trump would have gained two EC votes and Hillary Clinton would have two fewer – not enough to affect the outcome of that contest.