Obviously you haven't read it. The very next paragraph after the one David quoted says this....
Milien declined to comment on the discrepancy. However, it’s known that the Secret Service adjusts security depending on the size of the crowd and how much officials know about who’s in attendance. At some events, guests must pass through magnetometers. At others, they don’t.
That puts the lie to any claim that this was merely about "Latins". There are many issues involved that have nothing to do with the ethnicity of those attending.