Looks pretty corny, IMO.
What is Mexican? Seriously. Mexican is not an ethnicity, it's a nationality. Why do I say that? Because there are Mexicans of all races and ethnicities, and they are all equally Mexican. Their ethnicity, or blood, is not what makes them Mexican, it's their being raised in that country and its society. There are Mexicans of mostly Spanish blood, and Mexicans of mostly indio blood. There are Mexicans of Lebanese blood, and Hungarian blood. Mexico, like the United States, didn't exist before Europeans came over and started interbreeding with each other and the natives. A Mexican is simply a person who lives in Mexico, regardless of their ethnicity. Is there some specific blend of Nahua and Spanish blood that makes one more of a Mexican than someone with Spanish and Lebanese blood who was born in Mexico? No. They're both Mexican because of where they live, not because of their ethnicities.
Saying he's "Mexican blood" is stupid. If he was born and raised in Mexico and had Mexican citizenship, he'd be a Mexican. If he was born and raised in the US and had US citizenship, he'd be American. Is an Italian-ethnicity Brazilian not a Brazilian because of his blood? No. Every country in the Americas is a melting pot; unless you're of pure indigenous blood stop pretending you have "Mexican" blood. It's just as silly as "American" blood. Unless you accept that there's such a thing as "American blood," which most don't.