Mexican immigrants aren’t so fortunate. So when Cuban-Americans do what Rubio has done since arriving in the Senate 16 months ago and take a hardline against illegal immigration, Mexicans and Mexican-Americans have been known to cringe. After all, that’s easy for them to say.

Last year, Rubio came under criticism from fellow Latinos for getting wrong the year that his parents came to United States. It turned out that they left Cuba before Castro took power, making them immigrants and not refugees.

So here we have one more thing that Mexicans and Mexican-Americans can use against Rubio to try to take him down a peg or two. They’ll gladly remind him that he’s no better than they are, and that while some of their ancestors may have come to this country illegally, so did at least one of his.

As bad as this relationship has been, it’s about to get worse because of “grandpa-gate.” Stories like this make Rubio damaged goods and less useful in luring Latinos to the Republican ticket. That being the case, his vice presidential stock has to be plummeting. What good does it do the ticket for Rubio to be popular with whites and Cuban-Americans? Republicans are likely to get the majority of those votes anyway. His value is all wrapped up in how well he plays with Mexicans and Mexican-Americans. And right now, the answer is “not well.”