How popular?

How popular is Donald Trump with Hispanic voters?

It's a growing point of contention in the polling world.

By Steven Shepard

Donald Trump has promised to build a wall along the southern border. He’s referred to Mexican immigrants as rapists and criminals. He's attacked the Republican Hispanic governor of New Mexico.

He’s done much to alienate Latino voters since entering the presidential race, yet according to some polls he’s running ahead of 2012 GOP nominee Mitt Romney among them.

Trump and his surrogates frequently cite online NBC News/SurveyMonkey polls that have Trump winning just under a third of the Hispanic vote, more than Romney’s 27-percent performance against President Barack Obama. But other polling shows Trump well below historical benchmarks for winning GOP presidential candidates, and Hillary Clinton’s campaign believes Trump will win a smaller share of the Hispanic vote than any Republican in modern history.

The divergence in opinion over the presumptive Republican presidential nominee’s standing with Hispanic voters is a growing point of contention — nowhere more so than in the polling world.

While SurveyMonkey has Trump exceeding Romney’s 2012 performance among Hispanics, other polls conducted over the past few weeks show Trump a bit lower. In four other surveys conducted since mid-May — three live-interview telephone surveys and one internet poll — Trump ranged between 18 percent and 23 percent among Hispanics.

Most experts caution that national public polls aren’t great barometers of the Hispanic vote.

“Some of these polls only have 100 or 80 Latinos in them, so the margin of error is plus-or-minus 10 points,” said Matt Barreto, who is working for Hillary Clinton’s campaign, focusing on surveying Latinos, and is the co-founder of the polling firm Latino Decisions. “The sample size is always the first thing we look at. No one would rightly write a story about survey of 100 people.”

Polling Hispanic voters is widely recognized as a difficult endeavor: More than 60 percent of Hispanic adults in the U.S. don’t own a landline phone. Hispanics turn out at lower rates — 48 percent of eligible Latino voters casted ballots in 2012, compared to 67 percent of whites and 64 percent of blacks — making it more challenging, and more important, for pollsters to separate voters from non-voters.

Then there are the questions surrounding methods for surveying Hispanics. Not only are they harder to reach and less likely to vote than whites and African American, there is also a language issue — some naturalized citizens are more comfortable responding to surveys in Spanish, though fewer pollsters offer that as an option.

So it’s no surprise that Trump’s standing in polls among Latinos at this stage of the campaign is in dispute. An online survey last month conducted by SurveyMonkey, commissioned by NBC News, showed Trump capturing 28 percent of the Hispanic vote — one point better than Romney’s 2012 share. And this week’s NBC News/SurveyMonkey data has Trump reaching a new high among Hispanics: 32 percent.

Trump’s share of the Hispanic vote is only half the equation, however. The Latino population in the U.S. is growing rapidly: The number of Hispanics eligible to vote — U.S. citizens 18 and older — is projected to increase from 23.3 million in 2012, to 27.3 million in 2016, a 17-percent increase according to the Pew Research Center.

But because of lagging turnout rates, their relative increase as a share of the electorate has been smaller. Hispanics represented 10 percent of the electorate in 2012, up a point from 9 percent in 2008 and 8 percent in 2004. This year, it’s estimated the Hispanics will account for about 12 percent of all voters.

Hispanics also have a disproportionately low presence in swing states. In the states in which both nominees competed, Latino voters only made up larger shares than the national average in three of them: Nevada (18 percent), Florida (17 percent) and Colorado (14 percent).

(Increasing Latino populations have helped move New Mexico firmly into the Democratic column, however. And some Democrats hope Trump's alienation of Hispanics give the party a shot in Arizona, where Latinos made up 18 percent of the electorate in 2012.)

The polls showing Trump running stronger among Hispanics have prompted significant pushback, including a New York Times op-ed from political science professor Alan Abramowitz and American Enterprise Institute’s Norm Ornstein, headlined “Stop the Polling Insanity.”

“If the candidate were a conventional Republican like Mitt Romney or George W. Bush, that wouldn’t raise eyebrows,” Abramowitz and Ornstein wrote, citing the 28-percent SurveyMonkey finding. “But most other surveys have shown Mr. Trump eking out 10 to 12 percent among Latino voters.”

Jon Cohen, the chief research officer at SurveyMonkey, emphasized that one of the main advantages of their polling is a gigantic sample size that allows them to carve the electorate into small slices. This week’s wave of data includes interviews with 1,381 Hispanics.

One of the reasons why Trump is earning a larger share of the vote in SurveyMonkey’s polls than in other surveys, Cohen said, is because SurveyMonkey doesn’t offer an “undecided” option. Respondents can skip the question entirely – but if they choose to answer, they are limited to picking Trump and Clinton.

Cohen, who conducted more traditional telephone polling for the Washington Post and Pew Research Center before joining SurveyMonkey, said SurveyMonkey only asks questions in English, though they plan to add Spanish-language interviewing “soon.” But, he said, “My own experience from the phone world is it never made that much difference.”

Barreto, Clinton’s Latino pollster, dismissed SurveyMonkey’s Hispanic results in a phone interview, telling a POLITICO reporter: “You would do a better job just making numbers up.”

Barreto instead pointed to a Latino Decisions survey from April, conducted independently of Clinton’s campaign, showing the former secretary of state with a much larger advantage among Hispanic voters, 76 percent to 11 percent. (Latino Decisions conducts large-sample surveys in both English and Spanish, Barreto said.)

The accuracy of the Hispanic polling numbers isn’t just an academic question since Trump and his surrogates have been trumpeting favorable poll results among Hispanics, looking to counter the narrative that his candidacy will be a demographic disaster for the GOP. Senate Majority Leader Mitch McConnell said in an interview with CNN on Thursday that he’s worried Trump could damage the GOP’s relations with Hispanics for generations — like 1964 nominee Barry Goldwater did with black voters after Goldwater opposed civil-rights legislation.

The GOP has also invested in appeals to Hispanic voters since 2012 — when 1-in-10 voters were Hispanic, according to exit polls, and they broke heavily for President Barack Obama: 71 percent, to just 27 percent for Romney. Many in the party worry that significant elements of Trump’s candidacy — from his disparaging remarks about Mexicans in his announcement speech, to his recent pandering “taco bowl” tweet — threaten to undermine those efforts.

No one expects Republicans to carry the Hispanic vote since Democrats have dominated it for decades, winning at least 56 percent in each of the past nine presidential elections. Still, the share of the vote that the GOP nominee claims matters a great deal: Every Republican over that time who has won at least a third of the Hispanic vote has won the presidency — Ronald Reagan won 35 percent and 37 percent, respectively, in his two victories, and George W. Bush won 35 percent and 40 percent in his two bids. Only George H.W. Bush in 1988 won less than a third (30 percent) but still carried the day.

At the same time, there has been some measure of relative stability in the Hispanic vote, which means there’s likely a limit to how much Trump could sink the party’s vote share. The GOP’s low-water mark was in 1996, when former Sen. Robert Dole won 21 percent of Hispanics.

Barreto thinks Trump won’t even surpass Dole’s dismal performance.

“I would fully expect that he’ll be in the low teens on Election Day,” he said. “That doesn’t mean other people won’t put out polls showing Trump at 30 [percent among Hispanics]. I will ignore those. It’s just complete nonsense.”