I don’t see why they’re so worried. After all, Cinco has become just another Mardi Gras and St. Patrick’s Day, an excuse for any ole body to go out and drink.
Another consideration is that Cinco is supposed to be a Mexican thing, to celebrate the Mexican defeat of some French JV squad. I am not aware that Philadelphia is a big destination for Mexican immigrants. Its Hispanic immigrants, both legal and illegal, are probably Cubans and Dominicans, and not to mention Puerto Ricans who are natural born citizens. For the most part, Cubans already have legal status, (until one of Obama’s final acts as President, ending wet foot dry foot, one of the few good things he did in eight years), and like I wrote above, PRs are citizens by law (unfortunately), so the only kind of Philadelphia area immigrants who have “documentation” problems are its Dominicans. That said, neither Cubans, PRs, DRs, Gringos or anyone other than Mexicans have any business celebrating Cinco de Mayo.