Editor's note: Ruben Navarrette Jr. is a CNN.com contributor and a nationally syndicated columnist.
San Diego (CNN) -- Mitt, we hardly knew ye.
Or should I say, "primo!" As much as it embarrasses me to admit it, given some of his views and how he expresses them, the presumptive Republican presidential nominee and I could be distant cousins. Romney's father, George, was born in Chihuahua, Mexico, and so was my grandfather, Roman.
Que? You didn't know that Mitt Romney was half-Mexican? It's true. In fact, if he makes it to the White House, in addition to becoming the first Mormon in the Oval Office, he could also be the nation's first Hispanic president.
Don't laugh. Technically, Romney is just as "Mexican" as former New Mexico Gov. Bill Richardson, who was born of a Mexican mother and American father. When Richardson ran for the White House in 2008, he was often touted by the media as someone who would become the nation's first Hispanic president.
Yet, I would imagine that a lot of Americans aren't aware of this branch of the Romney family tree, and that's because it is not a detail that Romney usually talks about publicly -- and especially not on the campaign trail.
That changed this week when Romney -- in talking about his father, a self-made man who worked his way up from nothing to become head of American Motors Corporation, governor of Michigan and a Republican presidential candidate in 1968 -- told a crowd at the Rochester Opera House in New Hampshire that his father was born in Mexico and came to the United States at 5.
Romney's great-grandfather, Miles Park Romney, fled the United States and crossed into Mexico in 1885 to escape religious persecution. He helped build the Mormon enclave of Colonia Juarez in Chihuahua.
Miles Park Romney never became a Mexican citizen, and neither did his son, Gaskell, or grandson, George. They were all denied Mexican citizenship because statutes on the books in Mexico denied that right to American settlers and their offspring.
Speaking to the crowd in New Hampshire, Mitt Romney compared his father's story to those of countless other immigrants who have come to this country seeking economic opportunity.
My grandfather, a Mexican citizen, also came to the United States legally as a child in the early 1900s with his family, trying to escape the chaos of the Mexican Revolution. It was during the same time that Romney's grandfather, Gaskell, returned to the United States with his family, also legally and presumably for the same reason
Now, hold on to your sombrero.
I'm an American, born in the United States to parents who were born in the United States. In fact, three of my four grandparents were born in the United States. And yet, growing up, people in my hometown in Central California referred to me and other Mexican-Americans like me as "Mexican." That was the shorthand. But comparing bloodlines, you could say that Romney is more "Mexican" than I am. After all, Romney is just one generation removed from our ancestral homeland; I'm two.
This is ironic given that I've spent the last 20 years criticizing politicians who twist the facts, propose simple solutions and pick on those who don't have a voice.
And Romney has spent the last several months doing precisely that, just like he did during his failed 2008 presidential bid. He has used illegal immigration as a weapon against Republican opponents who propose reasonable solutions and in the process portrayed illegal immigrants, most of whom come from Mexico, as takers who come to the United States for free public benefits and ought not be rewarded with "amnesty."
We can expect Romney to continue that theme over the next week as he campaigns in South Carolina, where Republican primary voters will cast ballots on January 21 and where illegal immigration is a bigger issue than in Iowa or New Hampshire.
Lawmakers in the Palmetto State recently passed a tough Arizona-style immigration law that requires local and state police to determine the immigration status of anyone they suspect to be an illegal immigrant (read: Latinos).
It's an approach that is wildly unpopular with Latinos and which has the blessing of most of the Republicans running for president, including Mitt Romney.
And that's one reason why Romney, even if he is the GOP nominee for president, doesn't have much of a chance with Latino voters. Political experts say that a Republican would have to earn at least 30% of the Latino vote to win the White House. Given how he behaved in the primaries, Romney will be lucky to get 20%.
In fact, a recent poll of Latino voters by the Pew Hispanic Center put the figure at 23%. While it found a high level of anger with President Barack Obama among Latinos over his aggressive deportation policies, the poll also found that -- in a Obama-Romney matchup -- the Democrat would easily beat the Republican, 68% to 23%. That's saying something given that, according to the survey, Obama's job approval rating with Latinos is just 49%. The takeaway: You want to make Obama more popular with Latinos? Easy. Pit him against Romney.
Listen to Lionel Sosa, a San Antonio-based advertising executive and Republican strategist who has advised George W. Bush and John McCain. A few months ago, Sosa told The New York Times that Romney had blown his chance with Latinos.
"(Romney) can make as many trips to Florida and New Mexico and Colorado and other swing states that have a large Latino population," said Sosa, "but he can write off the Latino vote."
It was Romney who recently promised to veto the Dream Act if he's elected president and if Congress passes the bill. The legislation, which would allow undocumented students to stay in the country legally if they complete a college degree or join the military, is extremely popular with Latinos.
It was Romney who first attacked Texas Gov. Rick Perry for signing a law that allows illegal immigrants who live in Texas to pay in-state tuition at public colleges and universities. And it was Romney who later attacked former House Speaker Newt Gingrich for declaring that the GOP shouldn't support splitting up families and proposing a pathway for the undocumented to work legally in the United States.
It was Romney who, in the debates, came across as naive by suggesting that the illegal immigration problem could be solved by simply putting more "boots on the ground" and as dishonest by not acknowledging the contributions that illegal immigrants make to the local, state and national economies.
And it was Romney whose campaign put up, in New Hampshire, an offensive television ad that attacked Perry by linking him to Mexico and former Mexican President Vicente Fox, because Fox happened to agree with the Texas governor on letting illegal immigrants pay in-state tuition.
So the candidate who winds up vilifying Mexico is the same one whose father was born in Mexico? Who can make sense of this?
Listen up, Primo Mitt. You've made your bed. You're persona non grata with Latino voters, and it's your own fault. You can't win without them, but they can help make sure you lose.
We don't care where your family's from. What matters is where your heart is.
The opinions expressed in this commentary are solely those of Ruben Navarrette Jr.