Why Donald Trump May Be Weaker Than a Recent Poll Suggests
Donald Trump, president and chief executive of Trump Organization Inc., speaks during the Republican Party of Iowa's Lincoln Dinner in Des Moines, Iowa, U.S., on Saturday, May 16, 2015. Several current and potential candidates for U.S. president will speak during the dinner, hosted by the Republican Party of Iowa.
Photographer: Daniel Acker/BloombergNo matter the subject, for surveys to make sense, they have to be sampling the correct population. If you want to learn about car buyers, a researcher needs to interview people who buy cars. If you want to learn about diaper buyers, you need to interview people who buy diapers. If you want to learn about beer drinkers, you need to interview beer drinkers. And if you want to learn about likely Republican caucus-goers in Iowa or primary voters in New Hampshire, you should interview likely caucus-goers in Iowa and likely primary voters in New Hampshire.
So, with Sunday's NBC News/Marist University polls in Iowa and New Hampshire igniting a flood of news coverage highlighting Donald Trump’s “surge” (Politico) and “strong” showing (NBC and the New York Times), in these crucial early states, it’s worth examining who was actually interviewed. The poll's exact finding is that Trump leads the field in New Hampshire and comes in a close second to Wisconsin Governor Scott Walker in Iowa among what NBC News and Marist describe as “potential GOP voters.” While many polls use self-identified partisans as their primary sample, that’s a term not typically used by campaign pollsters, and is a much broader population than campaign pollsters would typically target.