Cinco de Mayo is already celebrated. (Cinco de Mayo celebrates Mexican victory over the French at Puebla in 1862.)
While I appreciate your irony, we already have a Mexican holiday here, Cinco de Mayo, that's celebrated as widely as the 4th of July. It marks the victory of the Mexican Army over the French at the Battle of Puebla. It's not an official state holiday but it might as well be because all the schools observe it with big fiestas as do most California communities .