In 2012, national polls in October suggested the presidential race was a virtual tie. The Real Clear Politics polling average gave Barack Obama a slight 0.7 point lead over Mitt Romney, but he actually won by almost 4 points. Of the final 11 national polls released in 2012, as reported on Real Clear Politics, 7 were a tie or had Romney ahead, while only 4 had Obama ahead.
Why were so many of the polls wrong? In part, because they failed to capture how minorities would vote. Unfortunately, some pollsters may be making the same mistakes in 2016 — and thereby underestimating Hillary Clinton’s lead in the polls.
In 2012, many polls underestimated how many minorities would vote and how many would vote for Obama. For example, a Politico poll released the morning of Election Day said the race was tied at 47 percent each for Obama and Romney. The poll said that 62 percent of Latinos supported Obama, while the exit polls reported 71 percent, and Latino Decisions reported 75 percent. Among the “another race” category, which is mostly comprised of Asian Americans, Politico reported that 47 percent supported Obama, while the exit polls reported 73 percent, and an Asian American Decisions exit poll reported 72 percent.
. . . In 2016, the country is even more diverse. Pollsters need to take steps to more accurately estimate the political attitudes and behavior of black, Latino and Asian American voters. Polls that are conducted only in English and that do few or no callbacks to try contact hard-to-reach populations are not going to accurately reflect the American electorate. Polls that are conducted via online panels need to ensure that they are not under-representing minority voters with less formal education and lower incomes. Finally, pollsters should take steps to make sure each racial subgroup in their poll is weighted to match the American Community Survey’s estimates for that particular group, not just their national sample overall.