It's a good thing then that so many of the Border Patrol guys, at least in Texas, are Hispanics (of course in Texas they are Tejanos, while us "Gringos" are Texians). I would imagine their accents and dialects are rather unusual, by Mexican standards that is. Probably even by Castillian standards.
Yeah, I'm reminded of the "Border Patrol" scene in Men In Black, where the (space) aliens are trying to blend in as Mexicans! LOL!