LOL page jump, I didn't see it.
Basically, there is no right answer, some mexicans are bad, some white people are bad, some black people are bad, and so on.
Quoted roughly from a speaker who was a White House aide in the 70's, (who emigrated from india) The ratio of "bad people" that will come from any race will greatly increase when moving somewhere else is easy. The more effort and the more brains it takes to move yourself or you family, the less likely a weak willed or substandard or even criminal person will move there.
Jumping the border is fairly easy (as compared to coming from India) so there is a lesser ratio of high quality people.
And, it takes one bad apple to ruin a whole sack of them, so becaue of bad mexicans, lotta people hate them all.