The Census Bureau released its annual national and state population estimates on Wednesday, noting that Idaho was the nation's fastest growing state for the year ending July 1, 2017. Election Data Services has extrapolated population growth from 2010-17 through to 2020, when the next Census will take place.
Among other things, the Census will determine how the 435 congressional districts will be reallocated next decade. This, in turn will determine changes to the electoral map. Each state receives an allocation of electoral votes equal to the number of congressional districts it has plus two for its Senators.
At this point, Texas and Florida look to be the big winners, gaining 3 and 2 electoral votes, respectively. Arizona, Colorado, North Carolina and Oregon will gain one each. As the number of electoral votes is fixed, these 9 increased votes must come from somewhere else. The current projection is that Alabama, Illinois, Michigan, Minnesota, New York, Ohio, Pennsylvania, Rhode Island and West Virginia are on track to lose one each. This projection is virtually unchanged from late 2016. The only difference is that Illinois, as opposed to Texas, would be allocated the final congressional district.