Two Saturday Surprises (EXIT POLL)

Two surprising results came out of Nevada and South Carolina Saturday

ByABC News
February 22, 2016, 11:40 AM

— -- Two surprising results came out of the Nevada Democratic caucuses and South Carolina Republican primary Saturday: in the former, Bernie Sanders’ showing among Hispanics; in the latter, Donald Trump’s performance among evangelicals. Each is worth a closer look.

There’s been some head-scratching about the Nevada entrance poll result; a piece in yesterday’s New York Times suggested that Sanders’ 8-point win among Hispanics was an unreliable finding, perhaps distorted by the vagaries of cluster sampling. (Clinton did well in precincts with sizable Hispanic populations, the piece pointed out, so why didn’t she win Hispanics?)

Entrance and exit polls aren’t perfect, for sure; the Times makes a fair point about their estimate of the Hispanic vote nationally in 2004 (the smaller, national exit poll produced a different result than the larger, more reliable cross-survey estimate). But extrapolating from precinct populations to caucus-goers is pretty fraught in itself. And in fact there’s a good reason for Sanders to have done well among Hispanics: They’re young.

It’s well-established that Sanders has been tearing up the house with young voters. He won 84 percent of caucus-goers under 30 in Iowa, 83 percent of under-30s in New Hampshire, 82 percent in Nevada. In a word, wow. (Context: Barack Obama, who famously whomped John McCain among young voters in 2008, managed 66 percent of their votes.)

So now let’s look at Hispanics. There were inadequate numbers of racial and ethnic minorities to analyze in Iowa and New Hampshire, but not so in Nevada. Hispanics accounted for 19 percent of voters – 213 respondents among the total sample of 1,024. That’s enough to evaluate given a probability-based sample.

How do they look? Per the entrance poll, Hispanics participating in the Nevada caucuses were nearly three times likelier than other caucus-goers to be younger than 30, and less than half as likely to be 60 or older.

Looking at their vote choices, Hispanics younger than 45 voted 70-27 percent for Sanders over Clinton in Nevada, while non-Hispanics under 45 voted almost exactly the same, 73-24 percent. There simply were proportionately more of the former. (Further, while the sample size of Hispanics age 45+ is small, their vote was more than 2-1 for Clinton – again, similar to her result among non-Hispanics in that age group.)

Internal validity takes us only so far, but there’s also external validity for the age-by-ethnicity differences in Nevada. Per the U.S. Census Bureau, the median age of Hispanics in the state is 27.5, while the median age of non-Hispanics is 42.4. The fact that Hispanics in the state are younger than non-Hispanics would seem to support the notion that Hispanic caucus-goers were younger, too, and thus more apt to be Sanders supporters.