...comes from the groups who hate the Chump:
There are 10.7 million more eligible voters today than there were in 2012. More than two-thirds of net growth in the U.S. electorate during this time has come from racial and ethnic minorities. Hispanics, blacks, Asians and other minorities had a net increase of 7.5 million eligible voters, compared with a net increase of 3.2 million among non-Hispanic white eligible voters.
The growth among non-Hispanic white eligible voters has been slower than among racial or ethnic minorities in large part because they are overrepresented in deaths due to an aging population. Non-Hispanic whites make up 69% of U.S. eligible voters, but accounted for 76% of all eligible voters who died (6.6 million of 8.7 million) between 2012 and 2016.
If, as Achen & Bartels argue in Democracy for Realists, social and group identity drives much of voting behavior, then this bodes ill for DDC.