Cinco de Mayo is one of the least understood holidays, but if we poke around a bit in last year’s headlines, maybe we can put together a comprehensive definition.

MSNBC’s “Way Too Early” called it a Mexican heritage celebration while a sombrero-wearing producer danced in front of the camera while shaking maracas and swilling tequila straight from the bottle. The 9th Circuit Court of Appeals ruled that a Northern California school district had the right to ban American flag T-shirts that day in order “to avoid violence.” Finally, José Canseco suggested a name change to “When Mexico Saved America’s Ass Day.”

That didn’t help much. Maybe Nancy Pelosi’s tweet today will shed some light.

But wait, there’s more! Rep. Pelosi’s tweet links to her official statement on Cinco de Mayo, in which she managed to slam the GOP.

“Today, we are reminded of the rich and diverse immigrant heritage that is the heart of our country. Immigration is the constant reinvigoration of America, and each generation of immigrants makes America more American. Yet Republicans continue their assault on hard-working immigrant families and continue to stand against the comprehensive immigration reform our nation so urgently needs.”

We don’t remember a previous generation of immigrants that made America more American by posing the threat of a “potentially violent disturbance” over the sight of an American flag on a T-shirt. Nevertheless, “Let us draw fresh inspiration from the Battle of Puebla, and let us renew our determination to achieve comprehensive immigration reform that honors the heritage, the history, and the values of our nation.”