The high-immigration states plus Illinois have had the nation's highest rates of domestic outflow, reflecting high tax rates, heavy regulation and high housing prices. In effect, they're trading Americans for immigrants. The political result is to make these states even more heavily Democratic.
This is apparent when you group states by political tendency. The 23 Republican states have grown 5.1 percent in 2010-15, the 11 target states 4.2 percent and the 16 Democratic states plus D.C. 3.2 percent. (I classify Colorado, Florida, Iowa, Nevada, New Hampshire, New Mexico, North Carolina, Ohio, Pennsylvania, Virginia and Wisconsin as target states. You can probably guess which of the others are Republican and Democratic.)
Republican states gained 2.3 million by migration, split evenly between immigration and domestic inflow. Target states gained 2 million, two-thirds from immigration and one-third from domestic inflow. In contrast, the Democratic states lost 1.8 from domestic outflow but gained 2.8 million immigrants — more than half the national immigration total.