It is an interesting survey, but it can also be misleading.  For many Americans their economic circumstances have declined over the last sixty years.  If those same people believe non-whites and immigrants are the reason, then they are are susceptible to a demagogue politician like Trump.   If they believe the political system has been bought out by plutocrats and corporations then they are more grounded in reality, but even then a political conman can still take advantage of them if the establishment candidates pretend nothing is wrong.