In the dying embers of the 2010 midterms, the Senate majority leader appeared to be on the ropes. Polls from a variety of well-known outlets showed tea party champion Sharron Angle leading him in the final weeks of the U.S. Senate race in Nevada. No less of an authority than Nate Silver, who correctly predicted 34 of the 36 Senate races that year, pegged Angle as the favorite in his final forecast. But on Election Day, the Nevada polls were proven wrong. Reid defeated Angle by nearly 6 points.”
So what happened? According to Senator Reid himself, “I would not be the majority leader in the United States Senate today, but for the Hispanics in Nevada.” Pollsters in Nevada knew that the Latino vote there would be important. How did they still manage to get this race so wrong ahead of time and miss the fact that Reid was poised for a resounding victory?
The answer? “The Harry Reid Effect.” The Harry Reid Effect happens when pre-election polls underestimate the Latino vote in such a way that seriously undercounts the actual support enjoyed by a candidate. The methodological and sampling errors in flawed pre-election polls combine with flawed voter turnout models (that underestimate Latino voter registration and turnout operations) to paint an overall misleading picture.
On methodology: Latino Decisions, which Time Magazine called “the gold standard of Latino-American polling,” provides a detailed explanation of what makes for solid methodology in Latino polling. The keys: have a sufficient sample size; survey a representative sample of the Latino population within the state or nationally; and conduct a representative number of interviews in Spanish. As Gary Segura, of Latino Decisions and Stanford University, explained to Talking Points Memo, “That was a huge flaw in the pre-election polling of the Reid-Angle race.”
Additionally, many polls have underestimated the Latino share of the actual electorate – due in part to the growing voter registration and turnout infrastructure in Nevada and other Latino-heavy battleground states. As Adam Nagourney of the New York Times notes today, “Mr. Reid has spent the last 10 years building a political machine that helped Mr. Obama win Nevada in 2008 and carried Mr. Reid to a re-election victory two years ago that stunned many pollsters. It is widely praised — even by Republicans — as one of the most effective voter-organizing and money-raising political organizations.” Investments in voter mobilization efforts in other key states, such as Colorado, Florida, Virginia, New Mexico, and Arizona are helping boots-on-the-ground activists tap into the growing number of eligible Latino voters.
So what does all of this mean for 2012?
Early indications show that “The Harry Reid Effect” may be at play in this election cycle. As Matt Barreto of Latino Decisions and the University of Washington explains in a detailed analysis, methodological problems with the Latino voter sample are to blame for a recent Monmouth University poll that showed President Obama only up 48%-42% among Latino voters nationwide. Monmouth’s finding stands in contrast to eight other national polls of Latino voters from impreMedia/Latino Decisions, NBC/Telemundo, CNN/ORC, and the Pew Hispanic Center. Those eight polls found President Obama’s head-to-head advantage to be, on average, 48 points: 70.3% to 21.9%. Barreto further explains that, in addition to skewing Latino-focused polls, poor Latino polling methodology may be affecting polling of the general electorate (in both national and state-specific polls) and skewing results several percentage points. As Gary Segura notes, “Anyone not interviewing in Spanish could be underestimating Obama’s support by about one to two percent, depending on the assumptions you make about Latino turnout in Nevada.”
Other polling experts are taking note. For example, Nate Silver of the New York Times’ FiveThirtyEight polling site wrote last week in a sub-post entitled, “Are Polls Underestimating Obama’s Hispanic Vote?” that:
In the past couple of elections, polls have underestimated Democrats’ standing in states with heavy Hispanic populations. (The two senate races that the FiveThirtyEight forecast called incorrectly in 2010 — Nevada and Colorado — are both states with a healthy number of Hispanic voters.) This may be because many polling firms that conduct interviews only in English miss some Hispanic voters who are more comfortable speaking Spanish. According to Matt Barreto of the polling firm Latino Decisions, which conducts bilingual interviews, primarily Spanish-speaking Hispanic voters are more likely to vote Democratic than those who have more English fluency.
Similarly, Nate Cohn of The New Republic’s Electionate polling blog wrote yesterday:
If the polls miss Latino turnout in 2012, that potentially changes the outcome of Colorado, Nevada, and Florida without much of a consequence for Iowa or Ohio. And it’s worth remembering that something like this may have been responsible for Reid and Bennet’s upset victories in 2010.