In 2012, President Obama carried the national popular vote by 3.9 percentage points. The exact white share of the 2012 electorate is still in dispute, but 2012’s exit polls pointed toward Obama carrying 81 percent of non-whites and 39 percent of whites. Hypothetically, if 2012 rates of turnout and support by group were to remain constant, Democrats’ popular vote advantage would swell to 5.1 percentage points in 2016 thanks to demographic shifts alone.
To give you an idea of that shift’s magnitude, here are some options for what Trump would need to happen in order to merely offset it: a) a 1 percentage point increase in the GOP share of the vote among non-Hispanic whites versus 2012; b) a 3 point increase of non-Hispanic white turnout, from 64 percent in 2012 to 67 percent in 2016; or c) a 3 point decline in non-white turnout from 56 percent in 2012 to 53 percent in 2016.
Of particular concern to Republicans should be the rapid declines in the non-Hispanic white share of the voting age population in two battleground states: Florida and Nevada. Between 2011 and 2015, Nevada’s non-Hispanic white voting age population fell from 58.2 percent to 54.9 percent, the biggest drop in the nation. Florida’s fell from 60.7 percent to 58.4 percent. In both states, the Hispanic share of the voting age population increased by about 1.5 percentage points.