Some of this is surprising, some less so... I assume New Hampshire is people who have moved up from Boston and commute? Florida and Arizona are retirees? Las Vegas probably attract people from far afield, too, I would assume, and probably the mountains around Colorado. Florida's first district is probably the military base, I guess, but I'm surprised San Diago isn't higher, and Hawaii. Alaska, I assume, is people moving up to work in oil and gas?
I'm surprised, though, about Wyoming, Vermont, Idaho's first, being so high. I'm also surprised at how low some of the big cities are... I thought there'd be more people moving to LA, San Fran, Chicago and NYC, but it seems Americans are as more likely to move to Arkansas and Oklahoma?
Small population states always have high percentages in this statistic.
Let's assume that there are equal numbers of persons moving from NH to MA and MA to NH. Those moving to MA will be dispersed among 9 districts, while those moving from MA to NH will be concentrated in two districts. There is pretty strong two-way migration between states. Retirees move to Florida or Arizona, but then some move back to live with relatives in their 80s. A wife who moved New Hampshire after her marriage returns to Massachusetts with her NH-born children after her divorce, etc.
Remember that this includes current residents who were
born in another state. California will have some 85 YO who moved from Oklahoma during the Depression. Alaska had very few people at the time of statehood. The current blue for Alaska is likely much paler than previous decades. The same is true to some extent for Wyoming. You're not seeing migration over the past decade (though there is census data on more recent residence).
You can also see the effect of cross-border moves, in places like Kansas City, Kansas; Indiana suburbs of Louisville and Chicago, Kentucky suburbs of Cincinnati, Wisconsin suburbs of the Twin Cities, Washington suburbs of Portland. West Virginia exurbs of Washington. It even shows up in places like the southern tier of New York.
The panhandle of Florida is likely retirees moving down from Alabama and elsewhere in the south. Retirees from the north are more likely to move to the peninsula. People from Miami or Tampa, probably think that Destin is too cold and that the people have an accent and use "y'all" instead of "youz guyz".
Since this is percentage of current residents, the number in New York and California particularly are diluted by foreign immigrants.
