“Some of these polls only have 100 or 80 Latinos in them, so the margin of error is plus-or-minus 10 points,” said Matt Barreto, who is working for Hillary Clinton’s campaign, focusing on surveying Latinos, and is the co-founder of the polling firm Latino Decisions. “The sample size is always the first thing we look at. No one would rightly write a story about survey of 100 people.”
Polling Hispanic voters is widely recognized as a difficult endeavor: More than 60 percent of Hispanic adults in the U.S. don’t own a landline phone. Hispanics turn out at lower rates — 48 percent of eligible Latino voters casted ballots in 2012, compared to 67 percent of whites and 64 percent of blacks — making it more challenging, and more important, for pollsters to separate voters from non-voters.
Then there are the questions surrounding methods for surveying Hispanics. Not only are they harder to reach and less likely to vote than whites and African American, there is also a language issue — some naturalized citizens are more comfortable responding to surveys in Spanish, though fewer pollsters offer that as an option.
So it’s no surprise that Trump’s standing in polls among Latinos at this stage of the campaign is in dispute.