Trump 's support had been modestly underestimated throughout his campaign .
Many observers blamed errors in polls , partially attributed to pollsters overestimating Clinton 's support among well - educated and nonwhite voters , while underestimating Trump 's support among white working - class voters .
Trump 's support had been modestly underestimated throughout his campaign , and many observers blamed errors in polls , partially attributed to pollsters overestimating Clinton 's support among well - educated and nonwhite voters , while underestimating Trump 's support among white working - class voters .