What will happen to the Electoral College after the 2020 Census?

The simplest way to predict the changes in each state’s number of electoral votes after the 2020 census is as follows:

1. Calculate the % change in each state’s population from the last census year (2010) to the most recent year you know the population for (2018).
2. Extrapolate the change rate per year to 2020 to predict the state’s population that year given its change rate for the time since the last census.
3. Divide the population predicted for a given state by the predicted population for all states combined to get the % of the US population predicted to be in each state in 2020.
4. Multiply the % value from step 3 by 435, round to the nearest whole number to get the estimated # of House districts, then add 2 (b/c each state gets a number of electoral votes = House districts + 2, one for each senator).
5. Voila! You now have the number of electoral votes each state is predicted to have after the 2020 census. You can of course then compare this to the number each state has now to see which states are gaining/losing 1 or more EV in this scenario. The answers are outlined below.

The following states are each expected to lose an EV:

• Minnesota
• Rhode Island
• West Virginia
• Alabama
• Michigan
• Ohio
• Pennsylvania
• Illinois
• New York

Meanwhile, the following states are each expected to gain one EV:

• Arizona
• Colorado
• North Carolina
• Oregon

Finally, Florida and Texas are each expected to gain 2 and 3 electoral votes, respectively, as both their populations have been growing much faster than the US as a whole since 2010.

These projections can be compared to those by other sources: 270towin.com, for example, indicates on each state’s election result page (you can view all of them here) whether the state is expected to lose or gain (an) electoral vote(s) after the 2020 census. The wording is sometimes kind of tentative (e.g. Colorado “may gain” an EV after 2020), but the general conclusions seem to agree with mine in almost all cases. The discrepancies are:

• I estimate that Illinois will only lose one EV, but 270towin.com claims it is on track to lose two.
• I estimate that Texas will gain three EVs, but 270towin.com says it should gain four.

Politico has conducted a similar analysis that has reached almost-identical conclusions to mine. Their list of states expected to lose an EV is: “Illinois, Michigan, Minnesota, New York, Pennsylvania, Rhode Island and West Virginia”. This is identical to my list but excluding Ohio and Alabama. Later in the article, however, they state that “Other states on the cusp of losing a House seat (and thus a vote in the Electoral College) in the next decade, if the current trends continue: California, Ohio and Alabama.” Their conclusion about California (but not about the other two states) is at odds with mine, since I did not conclude that California was on track to gain/lose any EVs.