At one time, sensible Republican leaders talked about broadening their base beyond white (non-Hispanic) voters.
Over the past three decades the white vote, in a presidential election, has shrunk from nearly 90 percent to 72 percent (in 2012).
Meanwhile, the white content of the Republican Party has stayed around 90 percent as the white percentage of the Democratic Party has shrunk to 56 percent.
If the GOP nominee wins the same share of the white vote as Mitt Romney won in 1012 (59 percent), he would need to win 30 percent of the nonwhite vote. Romney won only 17 percent of nonwhite voters in 2012.
Donald Trump is not popular with nonwhite voters. In a potential match-up against Clinton, only one in five nonwhite voters sides with Trump.
http://www.huffingtonpost.com/bob-burnett/5-things-weve-learned-abo_1_b_9794114.html