01/25/2012 06:07 pm ET Updated Mar 26, 2012

Who Is a Florida Primary Voter? The Latino Decisions Survey

Today, Univision/ABC/Latino Decisions released a national survey of Latinos, with a larger sample of Florida Latinos. The poll shows Romney besting Gingrich in the primary (both in Florida and nationally) and Obama trouncing both in the general.

But the poll has a clear flaw in how primary voters are defined. Respondents are asked whether they'd vote in the Republican primary as a yes/no question. But frequently pollsters ask voters to estimate their likelihood of voting in an election (only considering those most likely as potential voters). And importantly, Florida's primary is closed, meaning one already needs to be registered as a Republican in order to be eligible to vote in that contest. So a strong vote screen question in Florida would ask if voters were registered Republicans, and then only ask likely primary participation of those respondents.

As a point of comparison, the Washington Post/ABC national poll and the CNN/Time/ORC poll each use a two-pronged approach of identifying Republicans, and then further identifying likely primary voters. In the NBC/WSJ survey, respondents are asked if they would vote in the Democratic or Republican primary, "or wait for the general." But all three require respondents to clear a higher hurdle of simply yes/no to a Republican primary question.

We can tell the Latino Decisions poll's screen let in too many voters in a few ways. First, in the Florida subset, 26 percent of Democrats and 37 percent of independents say they will vote in the Republican primary, which seems high for a closed primary. Further, while 52 percent of Florida Latinos say they will vote in the Republican primary, Obama beats Romney overall by ten points (50/40), and Gingrich by 14 points (52/38). It simply doesn't make sense that an electorate where 52 percent are voting in the Republican primary, Obama exceeds majority support.

In the national survey, the same pattern holds. Latinos are divided on whether they'll vote in the Republican primary (45 percent yes, 44 percent no) with nearly a third (30 percent) of Democrats saying they will. And when asked for whom they'll vote in their state's primary, a fifth (20 percent) of Latinos nationally say they will vote for someone other than the four remaining candidates. Among Latinos in the general, Obama crushes both Romney (67/25) and Gingrich (70/22). Again, it seems unlikely that in a group giving Obama such a strong lead nearly half are Republican primary voters.

Polling for primaries is tricky. That makes it even more crucial to closely examine each state's contest, and each question's wording.