It turns out it's hard for pollsters to capture the opinions of America's fastest growing minority group. So hard, according to one researcher in the field, that many polling outfits have misfired in their attempts to survey Latino voters in this year's election.
Matt Barreto, founding principal at the research firm Latino Decisions and professor at the University of Washington, said on Thursday that his work has shown pollsters are often sloppy when they field a Latino sample.
Sometimes that means that they simply underrepresented Latino voters, which made up roughly 9 to 10 percent of the total 2008 electorate.
Other times it's because they neglected to talk to native Spanish speakers by conducting polls only in English. Or, Barreto said, some bi-lingual pollsters have offered instructions in English first, reducing the chances that a Spanish-speaking voter will remain on the line long enough to indicate a preference in the election. A low number of Spanish interviews carries the potential of producing a sample that is too assimilated and affluent, he said.
In a conference call with reporters, Barreto said any of these could potentially lead to big mistakes in the polls.
He pointed to the 2010 Senate races in Nevada and Colorado, where Democratic incumbents Harry Reid and Michael Bennet defied the consensus of many pollsters to emerge as the winners. Latino voters who ended up overwhelmingly supporting Reid and Bennet were misrepresented in polls of those races, Barreto said. It turned out to be a real embarrassment for the pollsters who predicted the incumbents would be defeated.
Barreto said he urges everyone to study the internals of a survey before drawing any grand conclusions from the top lines.
"You need to go in there and look at their minority demographics, and then you need to look at the vote results," he said.
Pollsters might be misreading the Latino electorate again this year. Barreto said his firm has seen a "very high enthusiasm and intent to vote" among Latino voters in 2012. That may not be showing up in every poll.
Most polls show President Obama with massive leads over Republican challenger Mitt Romney among Latinos. That's demonstrated by the 33-point gap in the PollTracker Average. But some polls have shown Obama with a modest single-digit lead among the group. Barreto said that's a clear sign to him that the pollster's methodology has a Latino problem.
"If Latinos are about 10 percent of the electorate, and you're putting Obama only plus six, you're missing about 2 to 3 points of support that Obama has," Barreto said.
Polling organizations typically strive for a sample that is representative of the overall electorate, but Barreto said they should look for a separate Latino sample that is actually emblematic of the Latino community too.