The migration timelapse
Press play. The left map is the net income and people that moved between the states each filing year, from the IRS. The right map is the political result in effect that year — switch it between President, Senate, and House, each with a running D-vs-R scoreboard (electoral votes and popular vote for President, seats for the Senate and House). The money drifts every year; the political side holds and then snaps at each election. Two separate public datasets, shown for the same states at the same time.
The run reaches back into the 1990s. The IRS did not report income (AGI) in the earliest years, so those show people only, and it changed its migration methodology with the 2011–2012 series (marked on the timeline), so figures before and after that seam are not strictly comparable.
Two independent public datasets shown for the same states at the same time: IRS tax-filer migration (net income and people, nominal dollars) and certified election results. They are not correlated here and this site does not connect one to the other. The right map holds each result until the next election; the migration map updates every filing year. Senate colors each state by its most recent Senate race; House colors each state by its delegation’s party balance. The scoreboard totals are the electoral college and popular vote for President, and the seat balance for the Senate and House.
See the underlying data on the election results and migration pages, and how it was assembled on the methodology page.