They were the O.B.H. The Original Bad Hombres. Catholic immigrants, they came to these shores as throwaways from their homeland -- the kind of place that today someone might call a "shit-hole country" where corrupt politicos had betrayed and cheated them. They arrived with nothing but the clothes on their backs, a cigar box of family photographs, a fierce work ethic and the character that comes from suffering. They were denied jobs because of their religion or ethnicity. And when they could find work, they did the sorts of dangerous and dirty jobs that Americans thought were beneath them -- only to be accused of taking jobs from natives. For their trouble, they were tormented by Know-nothings and subjected to decades' worth of insults, discrimination, and mistreatment. 

They got an up-close look at America's schizophrenia. Those who despised them wouldn't let them live nearby, but then those same people accused them of segregating themselves. They were told they'd never blend in, then accused of dividing their loyalty between this country and the one they left behind. They loved this land even when it didn't love them back. There was no mistaking them for the blue bloods who looked down upon them. Their blood is green. 

I speak of course about Irish-Americans. Saints alive. Whom did you think I was talking about? I suppose their story does sound familiar. 

Someone once asked me: "If you weren't Mexican, what would you be?" Without hesitation, I said: "I'd be ashamed."

But the five years I spent in Boston gave me the chance to fall in love with another community that knows all about loss and pain and heartbreak. 

These days, I think: If I couldn't be Mexican, I'd be Irish. It's a short walk. We're both Catholic, and we're not far removed from our immigrant roots. After all, what is an empanada but a more compact version of Shepherd's Pie? And we both play sad songs so we can cry and feel happy. 

My Irish friends pay tribute -- in a classic hymn that dates back to 1913 -- to a young man who heard "the pipes are calling" and had to leave Ireland, either to fight in World War I or to seek his fortune in America. Danny Boy is destined to come home "when summer's in the meadow," or "when the valley's hushed and white with snow," and "all the flowers are dying," only to find that his loved ones have passed away -- and he never got the chance to say good-bye. Such is the sadness of Ireland. 

As part of their own diaspora, Mexicans know this story -- of leaving, returning, leaving again -- by heart. Our anthem, which I heard at countless Mexican weddings growing up in central California, was popularized by the iconic Mexican crooner Vicente Fernandez. The classic song speaks of love and loss, the kind that tortures you and drives you mad. Having learned to love and lose, and accepting that you were wrong, you can only hope to make your way back to the arms of your beloved. Your last wish is to "Volver, Volver" (go back) to where you started, and make better choices.

Mexico's pain is evident in the lyrics of Bruce Springsteen's haunting ballad, "Sinaloa Cowboys": "For everything the north gives, it exacts a price in return." It's in the tears of the Mexican immigrant named Jose whom I interviewed last year on an avocado farm in San Diego County. He is proud to tell me that he has two teenage daughters in private school in Mexico, where they're learning English so they can have a better life. Jose hasn't seen his girls in 10 years, and he can't talk about them without his eyes filling with tears. Such is the sadness of Mexico.

To many Americans, Mexicans are -- like the Irish before them -- all about the "D's." They're dirty, dangerous, devious, dumb, defective and damaging to civilized society. A screed like that is offensive, but it's not original. 

A hundred and fifty years ago, people said the same -- and worse -- about our distant cousins from the Emerald Isle. They were wrong then. Just as they're wrong now. When Ireland sent its folks to America, it did send its best.

Happy St. Patrick's Day, lads.